Free Resource For Embedded Holic

Android and iPhone App with Siemens Online Support

2011-11-28T13:18:00.004+07:00

Siemens Automation annouced 2 new applications for iPhone, iPad and Android mobiles and Tablets.

The Online Support App enables you to access more than 300,000 documents on all Siemens Industry products, anywhere and anytime. No matter whether you face problems implementing your project, need help with troubleshooting, want to expand your facility or newly plan one.

You have access to FAQs, the latest firmware or software version downloads, manuals, certificates, siemens iphone online supportcharacteristic curves, application examples and tools, product news (e.g. announcement of new products), information on successor type in case of product phase-outs.

The start page gives you a quick overview of the latest articles. The search brings up hits for products and articles, and supports you with a personalized suggestion list. Under “mySupport” you can find your personal favourites with articles you need frequently. Additionally, you receive selected news on new
functions, important articles or events – in the News section.

What is Siemens Online Support

The Online Support offers you a comprehensive information system for all Industry Automation and Drive Technologies Service & Support subjects at any time.
Do you wish to extend your Know How, read up on services or exchange experiences with users of automation systems?
Convenient functions in the online support lead you directly to the desired information. Online Support always the first step – around the clock on 365 days of the year.

Benefits:

1. Direct, central access to founded, extensive information around the products, systems and applications with a number of programming, configuration and user examples.
2. Quick solution, also through exchange of knowledge amongst users in the Technical Forum and through contacting our expert in the Technical Support via support request.
3. Less on-site documentation required.
4. In 6 languages.
5. Help available 24h / 365 days in the year without time delay.
6. Always up-to-date.

You can get the app for free at the Apple App Store and at Android Market with the search terms:
“Siemens Industry Online Support”

Find more information:http://www.blogger.com/img/blank.gif

Apple iOS : Available on The App Store

Android : Availbale in Android Market

Resource : http://www.automationengineering.co.uk/2011/11/

ElectroDroid [Donate] v2.4 (Electronic Engineering Application For Your Android Phone)

2011-10-09T09:58:00.008+07:00

Requirements: Android 1.6+
Overview: Powerful collection of electronics tools and reference.A must for any enthusiast

ElectroDroid is a simple and powerful collection of electronics tools and reference; it includes:
• metric/imperial units and °C/°F;
• Decibel converter and tables;
• Frequency converter;
• ADC converter;
• ChipDB (IC pinout);
• New images in resources (vga, paral, usb, etc.)
• Firewire 9pin, XLR power;
• 78xx ic;
• PIC ICPS / AVR ISP;

• switch symbols;
• Resistor color code decoder (3-6 bands, with inverse look-up);
• Inductor color code decoder;
• Ohm’s law calculator;
• Reactance calculator;
• Voltage divider;
• Resistor ratio, value/series/parallel;
• Capacitor charge calculation;
• Operational amplifier;
• LED resistor calculator;
• LM317 calculator;
• Heat dissipation;
• Battery Life calculator;
• Inductor design tool;
• Voltage Drop calculator;
• PCB Trace Width calculator;
• Simple Filters calculator;
• NE555 astable calculator;
• Port pin-out (USB, Serial, Parallel, Ethernet, SCART, DVI, HDMI, S-Video, VGA, FireWire, Jack, XLR, RCA, DMX, ATX, Molex, EIDE, SATA);
• Resources (Resistivity table; Table of standard resistors and capacitors; Capacitor marking codes; AWG and SWG Wire size; Ampacity Table; Symbols and Abbreviations; Circuit Schematic Symbols; SI Units prefixes; Battery info; Boolean logic gate and algebra Theorems; 7400 info and pinout; ASCII code);
• Full support for EIA resistor series for all caluculators;
• New translations (Finnish, Turkish, Portuguese-Brazil);
...and more to come!

Click here for download this application for your android phone

GC-Prevue (Free Gerber Viewer)

2011-02-26T11:48:00.003+07:00

GC-Prevue is CAD/CAM software designed to help you work more efficiently with DPF, RS-274 (often called "Gerber") photoplotter and NC drill CAD output data, with a particular emphasis on Printed Circuit Board (PCB) applications. GC-Prevue also supports HPGL and Quest (Marconi Emma) plotter formats.
By verifying your CAD data from the photoplotter's point of view you will save time, money and headaches due to miscommunication with your photoplotting service and fabrication facilities.

Job files prepared using GC-Prevue are saved in the .GWK format, which is fully compatible with GraphiCode's product line, beginning with version numbers 4.0.0 and greater. (See "Error Messages Related to Loading Data Files “.) There are also several GraphiCode software packages sold under private labels that use the .GWK format. Contact your photoplotting bureau or PCB fabrication house to see if they accept jobs in GC-Prevue .GWK format.
GC-Prevue job files can contain all circuit, soldermask and solderpaste layer data, aperture tables (including custom aperture shapes) and drill information needed to effectively communicate with your photoplotting vendor and fabrication house.

Prevue will load Extended Gerber ("RS274X") and MDA FIRE file formats, which include aperture information. Use the Gerber or Auto input format when loading these files.

Download GC-Prevue V.18.3.2

CoolPack (A Collection of Simulation Tools for Refrigeration)

2011-02-26T11:04:00.004+07:00

CoolPack is a collection of simulation programs that can be used for designing, dimensioning, analyzing and optimizing refrigeration systems.

The simulation programs in CoolPack are divided into six categories - each represented by a tab in the Toolbar above. You can get an overview of the programs in a category by clicking on its Toolbar tab. Clicking on the icons in the Toolbar starts the individual programs.

The CoolPack program is freeware. For downloading the CoolPack tutorial please go to the tutorial page and download it. To install CoolPack you just run the downloaded file: Download CoolPack version 1.46 (app. 12 MB): CoolPack.exe.

You can also download Refrigeration Utilities as a "stand alone" program. The program is self-extracting. When you run this file, all the setup files will be extracted to a temporary folder. If you like, the dialog box gives you a possibility to change the name of the temporary folder. From the temporary folder you should run the SETUP.EXE file to install Refrigeration Utilities.

Download Refrigeration Utilities version 2.84 (app. 2.7 MB) : RefUtil.exe

Multipoint - EFI System (Part10. OPEN AND CLOSED LOOP)

2011-02-20T11:46:00.006+07:00

The terms open loop and closed loop refer to the operating mode of a computerized fuel system. When an engine is cold, the computer operates open loop (no feedback from sensors). After the engine warms to operating temperature, the system "kicks in" to closed loop (uses feedback from sensors) to control system operation.

Open Loop Operation

As was mentioned earlier, an oxygen sensor must heat up to several hundred degrees before it will functionProperly. This is the main reason computer systems have an open loop mode. The computer has preprogrammed information (injector pulse width, injector timing, air bypass valve position) that will keep the engine running satisfactorily while the oxygen sensor is warming up. When the engine and oxygen sensor are cold, no information flows to the computer. The computer ignores any signals from the sensors. The "loop of information" is open.

Closed Loop Operation

After the sensor and engine are warm, the oxygen sensor, and other sensors, begins to feed data to the computer. This forms an "imaginary loop" (closed loop) as electrical data flow from the engine exhaust, to the oxygen sensor, to the computer, to the injector, and back to the oxygen sensor. Normally, the computer system functions closed loop to analyze the fuel mixture provided to the engine. This lets the computer "double-check" itself.

Drawings show difference between closed I and open loop mode of computer operation.

Analog and Digital Signals

The signal from the engine sensors can be either a digital or analog type output. The output from the computer can also be analog or digital. Digital signals are instant on-off signals. An example of a sensor providing a digital signal is the crankshaft position sensor which shows engine rpm. Voltage output or resistance goes from maximum to minimum, like a switch, to report rpm in number form.

An analog signal progressively changes in strength. For example, sensor internal resistance may smoothly. Increase or decrease with temperature, pressure, or part position. The sensor acts as a variable resistor.

A-Digital signal is ON-OFF signal, like from wall light switch. B-Analog signal steadily increases or decreases voltage signal. It is not an instant ON-OFF signal.

Multipoint - EFI System (Part9. ENGINE SENSORS)

2011-02-19T09:31:00.015+07:00

An engine sensor is a device that changes resistance or voltage output with a change in a condition such as temperature, position, movement, etc. A modern electronic fuel injection system uses numerous sensors to improve efficiency. An Electronic Fuel Injection system might use many of the sensors.

In the Fig below how’s some of the conditions sensed by one computer system. Note that it checks everything from charging voltage to air conditioning operation.

Throttle position sensor

A throttle position sensor is a variable resistor or multi position switch connected to the throttle valve shaft. When the driver presses on the gas pedal for more power, the throttle shaft and sensor are rotated. This changes the internal resistance of the sensor. The change in current signals the computer and the computer can alter the air-fuel ratio as needed. One type of throttle position sensor is illustrated in Fig.3.29. Note how it mounts on the throttle body and that it has several contacts to change output resistance.

Sensors, located in many different locations on engine, may be used to feed information to computer.

Note typical conditions sensed and controlled by electronic means. (Buick)

Throttle position sensor. A-Sensor is mounted on throttle body over throttle shaft. B-View of inside of sensor. As throttle shaft rotates, it turns plate which alters internal circuit connections and resistance, sending electric current signals to computer. (Toyota)

Engine Coolant Temperature Sensor

An engine coolant sensor monitors the operating temperature of the engine. It is mounted so that it is exposed to the engine coolant.
When the engine is cold, the sensor might provide a high current flow (low resistance). The computer would adjust for a richer air-fuel mixture for cold engine operation. When the engine warms, the sensor would supply information (high resistance for example) so that the computer could make the mixture leaner.

Water temperature sensor usually is threaded into opening in block or head where it will be in contact with coolant.

Inlet Air Temperature Sensor

Air flow meter shows air temperature sensor. Sensor uses thermistor which is extremely sensitive to temperature changes. As temperature rises, resistance of thermistor decreases. (Subaru)

An inlet air temperature sensor measures the temperature of the air entering the engine, Cold air is dense than warm air, requiring a little more fuel. Warm air is NOT as dense as cold air, requiring a little less fuel. The air temperature sensor helps the computer compensate for changes in outside air temperature and maintain an almost perfect air-fuel ratio.

Charge Temperature Sensor

unlike air temperature sensor which senses only coldness of air, charge temperature sensor checks temperature of the air-fuel mixture. It is located in intake port just before intake valve. (Chrysler)

A charge temperature sensor, similar to an inlet air temperature sensor, measures the temperature of the air-fuel mixture. It is installed in the intake port, in front of the engine intake valve.

Crankshaft Position Sensor

A crankshaft position sensor is used to detect engine speed. It allows the computer to change injector openings as engine speed changes. Higher engine speed generally requires more fuel.
This sensor can be located on the front, rear, or center of engine. Its tip is close to the crank so that it can sense the teeth or notches as they rotate past the sensor. The magnetic field around the sensor, and current flow through the sensor, change as the crank rotates, allowing the computer to measure engine rpm.

Flap Air Flow Sensor

A flap air flow sensor measures the air flow into the engine. This helps the computer determine how much fuel should be injected into the intake manifold.
The air flow sensor usually mounts ahead of the throttle body assembly in the air inlet duct system.
In the Fig. below shows how a typical air flow sensor operates. At idle, the sensor flap is nearly closed. Sensor resistance stays high. This tells the computer that the engine is idling and needs very little fuel.

Flap air flow sensor tells computer whether engine is idling or at higher speed by measuring amount of air moving into engine. A -At idle speed, air flap is nearly closed. Responding to small current, computer produces short injection pulse width for small amount of fuel. B-Throttle open for more power, air flap swings open and sends strong signal to computer. Computer then sends wide pulse width to injectors for richer fuel mixture. C-Potentiometer is attached to sensor shaft. Wiping arm moves across potentiometer as flap moves. Depending on flap position, potentiometer will send weak or strong signal to electronic control unit.

As engine speed and air flow increase, air forces the flap to swing open. This moves the variable resistor to the low resistance position. The increased current flow now tells the computer that more air is flowing into the engine. The computer then increases injector pulse width as needed.
In the Fig. below shows how the flap type air flow sensor and potentiometer (variable resistor) are connected. Note that a weak spring is used to return the flap to the closed, idle position.

Cutaway shows how air sensor flap connects to and controls potentiometer. Strength of signal to computer depends on where wiping arm rests on resistor of potentiometer. (Volkswagen)

Mass Air Flow Sensor

A mass air flow sensor performs about the same function as a flap type sensor, but it sends more precise information to the computer. In the Fig. below is a newer type sensor found on some late model cars.
Basically, the mass air flow sensor uses a small electrically energized, resistance wire to detect air flow. The wire's temperature drops as air flows over it. The greater the air flow, the lower its temperature. The drop in temperature changes the wire's resistance, signaling the computer of more air intake. The opposite is true for low air flow.
A mass air flow sensor, sometimes called a "hot wire" sensor, is desirable because it automatically compensates for changes in air temperature and atmospheric pressure. It eliminates the need for an air temperature sensor and air pressure sensor.

Modern electronic, multi-point fuel injection system. Mass air flow sensor is located in duct ahead of engine. It detects air flow volume with fine resistance wire. (Chevrolet)

Mass air flow sensor with resistance wire. Wire is heated by electric current and is very sensitive to temperature. The greater the air flow past it, the lower its temperature becomes. The lower its temperature, the more the signal to computer changes. (Chevrolet)

Oxygen sensor

Oxygen sensor detects amount of oxygen in engine's exhaust. (Oldsmobile)

The oxygen sensor or exhaust gas sensor measures the oxygen content in the engine's exhaust gases. The oxygen content is an excellent indicator of whether the air-fuel mixture is too rich or too lean. The oxygen sensor is one of the most important sensors in modern electronic fuel injection systems. It actually checks the efficiency of the fuel system with the engine running.

Oxygen Sensor Construction

The oxygen sensor has a special ceramic core made of zirconium dioxide. The surface of the ceramic core is coated with platinum. The coated ceramic core has the ability to produce a voltage output when exposed to heat and a difference in oxygen levels on each side of the ceramic element. The ceramic voltage-producing device is enclosed inside a metal housing. Terminals are provided for connecting the sensor to the computer wiring harness.

Oxygen sensor is placed in exhaust system either at exhaust manifold or in pipe leading from exhaust manifold, as shown here. (Renault and AMC)

Cutaway of exhaust sensor. Note how it operates. Graph at right shows how oxygen content changes voltage of sensor's signal to computer. (Fiat)

Oxygen Sensor Operation

When the sensor is cold, it produces no voltage. The system then operates on data preprogrammed into the computer. When the oxygen sensor is heated above about 300 °F (149°C), it begins to produce a voltage signal.
When the fuel mixture is too rich, there is a small amount of oxygen in the engine exhaust gases. This produces a large difference in the oxygen levels on each side of the ceramic sensing device. Negative oxygen ions flow through the ceramic device and a voltage output is produced for the computer, Fig.3.41A. About a ONE VOLT signal is fed to the computer. The computer can then shorten injector pulse width to lean the air-fuel mixture slightly.
When the engine's fuel mixture is too lean, there is an excess amount of oxygen in the engine exhaust. This reduces the difference in the oxygen levels on each side of the sensor's ceramic element. Very few oxygen ions flow through the sensor and the sensor's voltage output drops to a fraction of a volt. this signals the computer to increase injector pulse width. This helps maintain an almost perfect air-fuel mixture.

A -Small amount of oxygen causes high voltage signal from sensor. B - Large amount of oxygen reduces signal strength. (Volkswagen)

Idle Speed Control

Most Motronics control idle rpm by a combination of the idle-speed stabilizer and ignition timing. The stabilizer is described in the section on LH-Jetronic. Inputs include rpm, closed-throttle signal, and engine temperature. The control unit sends on-off or digital signals to the idle-speed stabilizer. Early Motronics use the auxiliary air valve to increase air flow during warm-up, also described in the L-Jetronic section. In these, cold-engine idle rpm is increased according to temperature; it is an open-loop system.

Idle-speed control by idle air bypass. Idle-speed stabilizer handles coarse rpm corrections.

Timing Signals: RPM, TDC

For the most accurate measure of engine timing and speed, Multi – pint EFI systems read the position of the crankshaft directly, instead of from the ignition system as in L-Jetronic. Special sensors, shown in Fig. below, pick up signals from the flywheel teeth. Taking RPM and TDC timing signals from the crankshaft avoids inaccuracies from gear-lash or belt-drive such as when rpm and timing are determined in a camshaft-driven distributor, causing "spark scatter".

The rpm sensor (also called the engine-speed sensor) is an inductive-pulse sender that picks up pulses from a toothed wheel, usually the flywheel. The rpm signal can be displayed on a scope just as it is sent to the control unit, one blip or spike for each tooth as shown in Fig. below. It is so accurate it can sense an rpm change while the crankshaft turns only a few degrees.

RPM sensor (1) sends engine-speed signals from flywheel teeth; TDC sensor (2) sends one pulse per passing of set screw (arrow) each crankshaft revolution.

The TDC, or reference-mark sensor (reference from cylinder 1 TDC), is triggered by a set screw on the flywheel. Each time the screw passes the TDC sensor, the sensor signals one blip for each crankshaft revolution as shown in Fig. below. Both sensors are magnetic, with a soft iron core that stores the magnetic field. When a tooth in the flywheel or the reference pin moves through the magnetic field, the change induces an electrical voltage in the winding. This voltage is the input signal to the control unit. The sensor is known as a passive diffusion-field sensor because it does not require a current supply.

RPM sensor scope pattern shows one pulse per flywheel tooth

TDC sensor scope pattern shows one pulse per crankshaft revolution

One of these flywheel sensors provides input of rpm to the control unit. The other sensor provides input of TDC reference. The air flow sensor provides input of engine load. From the control unit ROM, an output signal to the coil primary sets timing advance and dwell for the next spark firing. Some engines operate with only one sensor that combines both functions, using a toothed timing wheel instead of the flywheel. Two missing teeth signal TDC, as shown in Fig. below.

In some Motronics, special timing wheel replaces starter gear ring or is mounted on front of crankshaft. Single sensor picks up rpm from teeth, and picks up TDC from gap in teeth.

Other Sensors

Other sensors besides those just covered can be used in a computer control system. Some of them include sensors checking the operation of the transmission, air conditioning system, brake system, and emission control systems. When information is required on any of these sensors, refer to a service manual. It will give the exact details of the specific system. It will explain its operation and how the sensor should be tested or serviced.

Multipoint - EFI System (Part8. AIR INLET DUCTS)

2011-02-19T09:22:00.002+07:00

Air inlet ducts on most fuel injected engines carry air from the air cleaner to the throttle body. Sometimes, the air flow sensor is mounted in this duct. The duct is usually made of plastic to reduce weight.

Clamps at duct fittings prevent leakage and keep airborne dirt out of the engine. Where ducts are placed between the air flow sensor and the intake manifold leakage could upset the air-fuel ratio. Fig.3.25 also shows where to look for components just discussed in the chapter. Note the locations of the fuel pressure regulator, fuel rail or manifold, throttle cable, throttle body, air bypass valve, cold start valve, and air flow sensor.

This air intake uses flexible duct to move air from air cleaner into intake manifold. Note location of air flow sensor, Leaks in duct could upset air-fuel ratio. (Fiat)

Multipoint - EFI System (Part7. THROTTLE BODY ASSEMBLY)

2011-02-18T09:15:00.012+07:00

The throttle body assembly for most modern fuel injection systems is used only to control air flow into the engine. A throttle valve, like the butterfly valve in a carburetor, is attached to the throttle cable and gas pedal. When the driver presses the gas pedal, the shaft rotates. This swings the throttle valve open to admit more air. This increases engine power for acceleration or pulling a load. The throttle body, itself, is usually made of cast aluminum. It mounts in the induction system just ahead of the intake manifold. As was shown in Fig below, it sometimes bolts to the inlet of the intake manifold.

Throttle body assembly only controls air flow to engine with most modern fuel injection systems. (Ford)

There are many throttle body designs for fuel injected systems. Two variations are shown here. (Ford and Honda)

Air Bypass Valve (idle speed control valve)

An air bypass valve, also known as an idle speed control valve, is frequently used to regulate engine idle speed. The air bypass valve normally mounts on the throttle body assembly. It can be controlled by either a temperature-sensitive device or by the computer. In the figure shows the action of the temperature (bimetal strip) operated idle air control valve. When the control valve and engine are cold, the bimetal strip holds. the air bypass open. This increases engine speed. When the engine warms, the bimetal strip bends and moves to close the idle air valve. This drops engine idle speed to normal.
The picture illustrates the basic action of a computer controlled idle air valve. When the engine is cold, the engine temperature sensor signals the computer. The computer knows that engine rpm should be increased to prevent engine stalling and stumbling. It then sends current to the idle air control valve. This opens the valve and allows air to bypass the throttle valve. The rest of the injection systems react to this increased air flow and engine idle speed increases, just as a carburetor fast idle cam increases cold engine idle rpm.
As the engine warms, the computer operates the idle air control valve to close off the bypass. Then, no extra air flows around the throttle plate and idle speed returns to normal again.

Air bypass valve acts like fast idle mechanism on carbureted fuel system. It speeds up engine idle rpm when it is cold. (Volkswagen)

Expansion and contraction of metals in bimetallic strip open and close air door in this air bypass valve. When engine is cold, metal contracts and opens door admitting more air. As engine warms, warm air, assisted by electric heat element, closes blocking plate to lower idle speed. (Renault and AMC)

shows a cutaway view of one computer controlled type of idle speed valve. When the engine is cold, the computer sends current to rotate the small dc motor in one direction. This turns the rotor and screw to pull the air bypass valve open. When the engine warms, the computer reverses the polarity to the motor so it turns the screw in the opposite direction, closing the valve.

Cutaway of idle air control valve operated by small dc motor and computer. Current from computer energizes motor which turns threaded shaft to open and close air valve. (Toyota)

Multipoint - EFI System (Part6. FUEL RETURN CIRCUIT)

2011-02-18T09:07:00.003+07:00

The fuel return circuit is made up of all the components that carry fuel from the outlet of the pressure regulator to the fuel tank, Fig.Below. This normally includes rubber fuel hoses, a steel fuel line, and necessary fittings.

The fuel return circuit allows circulation of fuel through the main fuel line, fuel rail, past the inlet to the injectors, through the regulator, return line, and back to the tank. This circulation prevents a heat buildup in the fuel. Heat could cause bubbles in fuel, upsetting fuel mixture.

Fuel Accumulator

A fuel accumulator dampens fuel pressure pulses and helps maintain fuel pressure when the engine is shut off. Fuel pressure fluctuations result from the action of the fuel pump and from the injectors constantly opening and closing. Too much pressure fluctuation could upset the operation of the pressure regulator.
The fuel accumulator acts like a "shock absorber." It can increase component life and help quiet system operation.
The fuel accumulator is simply an enclosed container with a spring-loaded diaphragm. Fuel pressure pushes the diaphragm down and compresses the diaphragm spring. This provides energy to maintain pressure or to counteract a sudden pressure drop.

Fuel accumulator is simply a small canister fitted with fuel inlet and outlet. Canister contains a spring and a diaphragm, the spring and diaphragm absorb pressure pulsations like a cushion. Left. Note names of parts. Center. When engine is running, fuel pressure compresses diaphragm spring. Right. When engine is stopped, spring presses up on diaphragm to maintain system pressure. (Volvo)

Multipoint - EFI System (Part5. FUEL PRESSURE REGULATOR)

2011-02-17T16:49:00.005+07:00

The fuel pressure regulator maintains a constant, preset pressure at the injectors. It is usually mounted on the fuel rail. After the fuel flows through the rail, it enters the pressure regulator. Extra fuel flows through an orifice in the regulator, into a return fuel line, and back to the tank.

Engine intake manifold vacuum is connected to the fuel pressure regulator. This allows the regulator to change fuel pressure with changes in engine load.

Fuel Pressure Regulator Construction

Figure below shows a cutaway view of a typical fuel pressure regulator. Study its construction. The basic parts of a fuel pressure regulator are:
FUEL INLET FITTING (allows fuel to enter pressure regulator from fuel rail).

a cutaway view of a typical fuel pressure regulator. Study its construction. The basic parts of a fuel pressure regulator are: 1. FUEL INLET FITTING (allows fuel to enter pressure regulator from fuel rail).

1. FUEL RETURN FITTING (allows excess fuel to flow out of rail and regulator and return to fuel tank).
2. CHECK VALVE (opens and closes to control fuel flow through regulator).
3. DIAPHRAGM (flexible disc that can move with changes in fuel pressure).
4. DIAPHRAGM SPRING (coil spring that pushes diaphragm toward fuel and closes check valve).
5. VALVE SEAT (attached to diaphragm, works with check valve to open and close fuel return).
6. VACUUM CHAMBER (allows engine vacuum to act on backside of vacuum diaphragm), Fig 2.18.
7. VACUUM FITTING (allows vacuum hose from intake manifold to connect to vacuum chamber).

Vacuum chamber shown at top is sealed by diaphragm. It receives vacuum from intake manifold. When intake manifold vacuum is low (engine accelerating or under load) spring keeps bypass valve closed so more fuel is delivered to injectors. (Ford Motor Co.)

Fuel Pressure Regulator Operation

Whenever the electric fuel pump is operating, fuel flows into the regulator's pressure chamber from the fuel rail. The fuel, being under pressure, pushes on the regulator diaphragm. However, there is still not enough pressure to cause the return valve to open. Additional force must be supplied by engine vacuum.

When the engine is running, vacuum enters the vacuum chamber of the regulator and exerts a "pull" that, together with the force of the fuel in the opposite chamber, causes the diaphragm to flex and open the return valve. Excess fuel pressure is bled from the system to lean the fuel mixture. The excess fuel returns to the fuel tank. See Fig.Below.
Under rapid acceleration, the engine requires a richer mixture. The fuel pressure regulator is designed to help richen the mixture. This is what happens:
As the engine begins to accelerate, engine vacuum drops.
Since fuel pressure alone cannot keep the diaphragm flexed, it returns to its former position, closing the return valve.
This causes fuel pressure to build up higher to richen the mixture for more power.
Keep in mind that the computer and sensors are monitoring fuel mixture and other variables. They work with the pressure regulator to maintain the most efficient air-fuel ratio for the needs of the engine. Fig.Below shows a cutaway view of a fuel rail and its fuel pressure regulator. Note how the regulator acts to maintain fuel pressure in the rail and to the injectors.

Cutaway shows how vacuum affects regulator action. When engine vacuum is high (engine at low speed or idle) diaphragm flexes in direction of vacuum. This opens valve and allows fuel to bypass and return to fuel tank. At low vacuum (engine under load) diaphragm flexes down to close bypass valve and increase fuel pressure. (Honda Motor Co.)

Multipoint - EFI System (Part4. FUEL RAIL ASSEMBLY)

2011-02-17T16:40:00.005+07:00

The fuel rail assembly, also called a fuel log, feeds fuel to all of the injectors, Fig. 3.11. The fuel pressure regulator and sometimes the cold-start injector attach to the fuel rail. The fuel rail can be a length of steel tubing or a cast metal block.

As shown in Fig.below, fuel enters the fuel rail from the electric fuel pump. Equal fuel pressure forms inside the rail and at the inlet to each injector. The pressure regulator bleeds off excess fuel to maintain the proper pressure in the system. This allows cool fuel to constantly circulate between the fuel rail and the fuel tank.
A service fitting is a threaded orifice for bleeding off pressure and for installing a pressure gauge. One is normally provided on the fuel rail. It is usually covered with a metal cap that keeps out dust and dirt.

Fuel rail assembly. Fuel pressure regulator and sometimes cold-start injector are considered part of this assembly. (Buick)

Electric fuel pump supplies fuel to fuel rail. Note that this rail consists of a length of tubing rather than a casting. (Fiat)

Multipoint - EFI System (Part3. GASOLINE INJECTION)

2011-02-17T13:10:00.006+07:00

An injector for a gasoline injection system is simply an electrically operated fuel valve. When energized by the computer, it must open and produce a uniform fuel spray pattern in the intake manifold. When re-energized, it must close quickly, without leakage.

Injector Construction

Most modern injectors are made of metal and plastic. Rubber O-rings seal joints where parts fit together. Usually, the injector fits into a hole machined into the intake manifold. However, as will be discussed in the next chapter, some systems have the injector in the throttle body assembly.

Cutaways show important components of an injector. (Chrysler)

Refer to this illustration.

1. ELECTRIC TERMINALS (electrical connection for circuit between injector coil and computer).
2. INJECTOR SOLENOID (armature and coil that opens and closes valve).
3. INJECTOR SCREEN (screen filter for trapping debris before it can enter injector nozzle).
4. NEEDLE VALVE (end of armature shaped to seal against needle seat).
5. NEEDLE SEAT (machined surface around the hole in end of injector against which the needle valve tip presses to form a seal).
6. INJECTOR SPRING (small spring that returns needle valve to closed position).
7. O-RING SEAL (rubber seal that fits around outside of injector body and seals in intake manifold).
8. INJECTOR NOZZLE (injector outlet that produces fuel-spray pattern).

EFI injector operation. A-Current through injector coil builds magnetic field. Magnetism attracts and pulls up on armature to draw injector needle off its seat. Gasoline sprays out. B-Current flow stops when computer breaks circuit. Injector valve closes stopping fuel spray.

Gasoline Injector Operation

In a simplified way, Above picture illustrates the operation of a gasoline injector. When the computer sends current to the injector coil, the coil develops a magnetic field. Like an electromagnet, the field attracts and pulls on the injector armature. The armature moves up into the coil's field. The needle is then lifted off its seat and let’s fuel spray out the nozzle into the intake manifold.
When the computer shuts off current to the injector coil, the magnetic field collapses. This lets the injector spring push down on the armature forcing the needle against its seat. This blocks fuel flow.

Injector Pulse Width

Injector pulse width refers to the length of time or duration that the injector is open. The computer controls injector pulse width. A long pulse width richens the fuel mixture because more fuel would spray into the intake manifold on each cycle. A short pulse width would lean the mixture because the injector would be kept closed longer between pulses.

Injector pulse width means the amount of time that computer sends current to injector to keep valve open. A-Short pulse causes less fuel spray because injector valve is not open long percentage of time. Mixture is leaner. B-Long pulse keeps valve open more of the time. Mixture is richer

Above picture illustrates short and long injector pulse widths. Note that the square sine wave (sine representing voltage change) denotes the pulse width. When the wave moves up from zero, indicating voltage supply to the injector, the injector is open. When the wave moves back down to zero (base line), the injector is closed because there is no voltage and current flow.
When the square wave is shorter, Fig.A, the injector pulse width is shorter and the fuel mixture is leaner. When the square wave is longer, Fig.B, the pulse width is longer and the mixture is richer.
With many systems, the computer cycles the injectors open and closed several times a second. By changing the percentage of ON and OFF times, it can control the air-fuel mixture ratio.

Multipoint - EFI System (Part2. ELECTRONIC CONTROL UNIT (COMPUTER))

2011-02-17T12:55:00.005+07:00

The computer, or electronic control unit (ECU), is the "brain" of the fuel injection system. The sensors and wiring harness serve as the "nervous system": checking temperatures, positions, and other considerations for proper injection system operation. Fig below shows how electric current is fed to the computer from various sensors and how the computer feeds current to the injectors.
A car's computer is actually a preprogrammed microcomputer (preset, miniaturized electronic circuit). It has microscopic electronic circuits which are formed inside integrated circuits (ICs).
An integrated circuit is an electronic chip or circuit manufactured by photographically reducing a circuit and placing it on a special semiconductor (transistor type) material. This enables the computer to have literally hundreds or thousands of transistors, resistors, capacitors, and similar components in a very small space. Different circuits are provided in the computer for performing different functions.

Engine sensors send flow of information to electronic control module (on-board computer) in form of small electric currents. The module, acting on signal received, feeds current that operates injectors.

On-board computer contains thousands of miniaturized circuits.

The picture is showing a photo of the inside of an automobile computer. Note the very small components, especially the integrated circuits.
The on-board computer is about the size of a car radio and is often placed in the passenger compartment. Since computers are sensitive to vibration, extreme temperature change, and moisture, they are sometimes located behind or under the dash panel, Fig.3.7. This places them away from engine heat, moisture, and the elements in the engine compartment.
There are four basic parts or sections to a car's computer: input/output devices, central processing unit, power supply, and memories.

Input/output Devices

The input/output devices are electronic circuits that convert signals from sensors into digital (on/off or computer) signals for use in the central processing unit (brain or calculator section) of the computer. The devices (circuits) can also change computer language into electrical signals to operate system components.

On-board computer is usually behind instrument panel (dash). In this location, it is shielded from damaging engine heat and vibration. Some computers are mounted on air cleaner or elsewhere in engine or passenger compartment. (Cadillac)

Central Processing Unit

The central processing unit performs mathematical functions or logic functions to deliver the correct air-fuel ratio and to operate other system devices. It uses digital signals from the input devices to determine what is going on during vehicle operation and what should be done to increase efficiency.

Power Supply

The power supply in a car's computer prevents voltage fluctuations that could affect computer operation. A computer relies on very smooth dc current, mainly from the car battery. The power supply simply regulates input voltage to other parts of the computer.

Computer Memories

Most computers have three basic types of memory circuits: read only memory, random access memory, and programmable read only memory.

The read only memory (ROM) is programmed data that can only be analyzed by the computer itself. It is information used by the computer in performing the various functions. The ROM program cannot be changed. If the battery or voltage supply is disconnected from the computer, the data in the ROM will remain in the computer.

The random access memory (RAM) is temporary information held in the computer. It is like a "note pad" of inputs and outputs. Data such as self-diagnosis codes can be pulled out of RAM. If battery voltage is removed, all information is erased from RAM.

The programmable read only memory (PROM) has information on the particular make and model car. It has data about engine size, vehicle weight, transmission type, rear axle ratio, etc. As you will learn in the chapter on fuel injection service, the PROM is normally removed and reused when replacing the central processing unit (computer). If voltage is disconnected from the PROM, it will retain its information.

Multipoint - EFI System (Part1. FUEL INJECTION)

2011-02-17T11:48:00.008+07:00

Fuel injection is a means of metering Fuel into an internal combustion engine. In modern automotive applications, fuel metering is one of several functions performed by an "engine management system". For gasoline engines, carburetors were the predominant method to meter fuel before the widespread use of fuel Injection. However, a wide variety of injection systems have existed since the earliest usage of the internal combustion engine. The primary functional difference between carburetors and fuel injection is that fuel injection atomizes the fuel by forcibly pumping it through a small nozzle under high pressure, while a carburetor relies on the vacuum created by intake air rushing through it to add the fuel to the air stream. The fuel injector is only a nozzle and a valve: the power to inject the fuel comes from further back in the fuel supply, from a pump or a pressure container.

A modern gasoline injection system, using pressure from an electric fuel pump, sprays fuel into the engine intake manifold. See Fig below. Like a carburetor, it provides the correct air-fuel mixture for specific engine operating conditions. However, PRESSURE, not engine vacuum (suction), feeds the fuel into the engine cylinders. This makes gasoline injection very efficient.

Gasoline Injection Advantages

Gasoline injection has several advantages over a carburetor. The most important of these are:
Improved atomization. Fuel is forced into the intake manifold under pressure. This helps break the fuel into a fine mist.
Better fuel distribution. Flow of fuel vapors to each cylinder is more uniform.
Smoother idle. A leaner fuel mixture can be used without rough idle because of better fuel distribution and low-speed atomization.

Simplified cutaway shows action of most common fuel injection system for a gasoline engine.

1. Improved fuel economy. Efficiency is high because of more precise fuel metering, atomization, and distribution.
2. Lower emissions. Lean, efficient air-fuel mixture reduces exhaust pollution.
3. Better cold weather operation. Injection gives better control of mixture enrichment than a carburetor choke.
4. More engine power. Precise metering of fuel to each cylinder and increased air flow can produce more horsepower.
5. Simpler. Late-model, electronic fuel injection systems have fewer parts than modern computer controlled carburetor systems.

Gasoline Injection Timing

The timing of a gasoline injection system relates engine valve action to the time when fuel is sprayed into the engine intake manifold. There are three basic classifications of gasoline injection timing: intermittent, timed, and continuous. An intermittent gasoline injection system opens and closes the injection valves independently of the engine intake valves. This type of injection system may spray fuel into the engine when the valves are open or when they are closed.
Another name for an intermittent injection system is MODULATED injection system. This is one of the most common types of gasoline injection. A timed injection system squirts fuel into the engine right before or as the intake valves open. It is timed to the opening of the engine intake valves. The best example of timed injection is a diesel injection system.
A continuous gasoline injection system sprays fuel into the intake manifold all of the time. Anytime the engine is running, some fuel is forced out of the injector nozzles and into the engine.
The air-fuel ratio is controlled by increasing or decreasing fuel pressure at the injectors. This increases or decreases fuel flow Out of the injectors. A continuous type injection system is frequently used on several foreign cars and on a few American cars.

Note four subsystems of an electronic gasoline injection system (dashed line boxes). Sensor systems feed data to computer. Computer uses this data to operate fuel delivery system. Parts of air system can a/so be controlled by computer.

Fuel Delivery System

The fuel delivery system cleans and meters the right amount of fuel for varied driving conditions. It is made up of an electric fuel pump, fuel filter, fuel rail, pressure regulator, injectors, and connecting lines and hoses.
The electric pump forces fuel out of the tank, through the lines, and into the pressure regulator. When the computer energizes the injectors, fuel sprays into the engine. Extra fuel bleeds out of the pressure regulator and back to the tank.
Note: Many of the parts (fuel pump, filters, lines, etc.)

Air Induction System

An air induction system for Electronic Fuel Injection provides clean air and delivers it to the engine cylinders. This system, typically, consists of an air filter, throttle body, throttle valve, intake manifold, and connecting air ducts.

Design of air induction systems will vary depending upon engine and fuel system design. However, they all have an air filter for removing airborne impurities, a throttle valve for controlling air flow into the engine, and other related parts.

Sensor System

The Electronic Fuel Injection sensor system keeps track of engine operating conditions and passes this information to the computer. See Fig below. A typical Electronic Fuel Injection sensor system includes an oxygen (exhaust gas) sensor, engine coolant temperature sensor, air inlet temperature sensor, throttle position sensor, intake manifold pressure (vacuum) sensor, and other sensors.
Just as your body can sense a change in its surroundings, (touching a hot stove for example), the sensor system can sense a change in the operation of many vehicle systems. It enables the modern fuel injection system to CHECK and CORRECT itself.

These diagrams summarize computer control system. A-Computer or ECU inputs. B -ECU (electronic control unit] outputs of various system parts. (Renault)

Computer Control System

The computer control system processes information and controls operation of the Electronic Fuel Injection system and certain other automobile systems.
A computer wiring harness carries current to and from the computer. Sensors from the engine, transmission, air conditioning system, and other systems send electrical information to the computer through the harness. Then, the computer can operate the injectors, transmission, ignition system, emission control systems, and other components for maximum efficiency.

CURCUIT CELLAR (JANUARY 2011) ISSUE 246

2011-02-09T10:44:00.002+07:00

Content : Embedded Applications, MCU-Based Brake Control system, Mobile Application Development (A Sound Detection Algorithm), Stress Free Probing, Embedded energy Conservation, “smart” network Access explained, Surge disaster preparedness Tips.

Click Here To Download

Cypress Warp 6.3

2011-02-06T11:50:00.002+07:00

Warp users describe electronic designs using VHDL and then compile and synthesize those descriptions to program Cypress devices, such as small PLDs, MAX340 EPLDs, FLASH370, Ultra37000, Delta39K and Quantum 38K CPLDs.
Warp consists of :
• The Warp VHDL IEEE 1076/1164 compliant compiler to translate VHDL text descriptions into JEDEC files that can be mapped onto programmable devices.
• On the PC platforms, Warp also contains an FSM editor and Active-HDL Sim, the post-synthesis timing simulator from Aldec, Inc.

Click link below to download Cypress Warp 6.3

Cypress Warp 6.3 With Serial.zip.001
Cypress Warp 6.3 With Serial.zip.002
Cypress Warp 6.3 With Serial.zip.003
Cypress Warp 6.3 With Serial.zip.004
Cypress Warp 6.3 With Serial.zip.005
Cypress Warp 6.3 With Serial.zip.006
Cypress Warp 6.3 With Serial.zip.007
Cypress Warp 6.3 With Serial.zip.008
Cypress Warp 6.3 With Serial.zip.009
Cypress Warp 6.3 With Serial.zip.010
Cypress Warp 6.3 With Serial.zip.011

Honda Civic (96-98) Service Manual

2011-02-06T10:35:00.005+07:00

This service contains information for the 1996 - 1998 Honda CIVIC. It is devided into 24 sections. The first page of each section is marked with a black tab that lines up with its corresponding thumb index tab on this page and the back cover. You can quickly find the first page of each section without looking through a full table of contents.

The main chapter are covered : General Info, Special Tools, Specifications, Maintenance, Engine, Cooling, Fuel and Emissions, Transaxle, Steering, Suspension, Brakes (Including ABS), Body, Heater and Air Conditioning, Electrical, and SRS.

Click link below to download.

Honda Civic (96-98) Service Manual.zip.001
Honda Civic (96-98) Service Manual.zip.002
Honda Civic (96-98) Service Manual.zip.003
Honda Civic (96-98) Service Manual.zip.004
Honda Civic (96-98) Service Manual.zip.005
Honda Civic (96-98) Service Manual.zip.006
Honda Civic (96-98) Service Manual.zip.007
Honda Civic (96-98) Service Manual.zip.008

Serial Port Test Utility With "Visual Basic 6.0" Code (Programming Serial Port With Visual Basic 6.0)

2011-01-29T08:53:00.003+07:00

This is a preliminary serial port test utility. The scope of the project has drifted from a simple test app to a full utility. I am releasing the code as a beta test and to attempt to get some feed back. I understand that the structure of the design is not "robust" as this project's scope has wandered. My primary concern is to determine the functionallity likes and dislikes from other programmers needs. The final version will include Text file logging of data sent and received. Please feel free to make suggestions for improvements. The basic functionality of the code has been tested on both Win NT and Win2000. Note that all the error handling is not complete nor has the app been tested by anyone but me.

Click Here To Download

Low Cost (8-Channel) Thermocouple Signal Conditioning With Analog Multiplexer and Analog Optocoupler.

2011-01-25T16:08:00.013+07:00

In the current project will be created a signal conditioning for thermocouple equipped with an analog multiplexer, the total input for this circuit is 8-channel thermocouple input.

Some of the problems in a thermocouple signal conditioning is required strengthening gain and also giving a pretty good filter so the noise do not stay in the thermocouple which has a weak signal.

Some of the main components in this project are:
1. Multiplexer Analog Input For Thermocouple (ADG507A)
2. Thermocouple Amplifier (AD595)
3. Op-Amp (INA126)
4. Analog Optocoupler (HCNR201)

ADG507A

The ADG507A are CMOS monolithic analog multiplexers with 16 channels and dual 8 channels, respectively. The ADG507A switches one of eight differential inputs to a common differential output, depending on the state of three binary addresses and an enable input. Both devices have TTL and 5 V CMOS logic compatible digital inputs. The ADG507A are designed on an enhanced LC2MOS process, which gives an increased signal capability of VSS to VDD and enables operation over a wide range of supply voltages. The devices can operate comfortably anywhere in the 10.8 V to 16.5 V single or dual supply range. These multiplexers also feature high switching speeds.

AD595

The AD595 is a complete instrumentation amplifier and thermocouple cold junction compensator on a monolithic chip. It combines an ice point reference with a precalibrated amplifier to produce a high level (10 mV/°C) output directly from a thermocouple signal. Pin-strapping options allow it to be used as a linear amplifier-compensator or as a switched output setpoint controller using either fixed or remote setpoint control. It can be used to amplify its compensation voltage directly, thereby converting it to a stand-alone Celsius transducer with a low impedance voltage output.

You can see the AD595 output voltage as a representation of the temperature thermocuople complete in datasheet. The Appropriate thermocouple type for the AD595 is J and K-type thermocouple.

INA126

The INA126 is precision instrumentation amplifiers for accurate, low noise differential signal acquisition. Their two-op-amp design provides excellent performance with very low quiescent current (175μA/channel). This, combined with a wide operating voltage range of ±1.35V to ±18V, makes them ideal for portable instrumentation and data acquisition systems. Gain can be set from 5V/V to 10000V/V with a single external resistor. Laser trimmed input circuitry provides low offset voltage (250μV max), low offset voltage drift (3μV/°C max) and excellent common-mode rejection.

You can see the basic connection and how to setting the gain for INA126 in the picture below.

How The Circuit Work

The complete picture thermocouple signal conditioning circuit as shown below.

Instal the thermocouple sensor in the channel that you want on the input terminals. For example if you want to put on channel 1 you can plug thermocouple in the terminal J1. Do addressing for ADG507A multiplexer in accordance with the input channel that you want. For reference ADG507A addressing you can use the reference to the ADG507A datasheet which you can download at the bottom part.

Thermocouple output on this ADG507A will be given to the AD595 as an information signal from the thermocouple. ADG595 will process this data and then converted and amplified into a voltage that represents the signal from the thermocouple. The magnitude of this voltage can you see on the AD595 datasheet.

The output of the AD595 is still too small so need to be strengthened again using the INA126 op-amp, Set INA126 Gain by adjusting the value of VR1 to get the gain that you want. Do not forget to set the offset of the INA126 with setting VR2, adjust VR2 until the voltage at pin5 of ICINA126 = +/- 0 Volt.

HCNR201

Actually the output of the INA126 is good enough to be used, but sometimes there are problems when the tip of this thermocouple we attach to the body of the equipment that containing the ground, therefore in this series are equipped with analog isolatar HCNR201 to isolate the output voltage of the INA126 to not blend with another ground. In the picture you can see, there are two power supply that is VCC1 and VCC2, VCC1 is devoted only to the Thermocouple where ground VCC1 (GND) should not be fused with the another ground, GND is ground only for a series of ADG507A, AD595 and INA126. While VCC2 with ground GNDA is ground that can be associated with other equipment such as ground on data acquisition board.

HCNR201 is high-linearity analog optocoupler consists of a high-performance AlGaAs LED that illuminates two closely matched photodiodes PD1 and PD2, as shown in Figure 1. The input photodiode PD1 can be used to monitor, and therefore stabilize, the light output of the LED. As a result, the on linearity and drift characteristics of the LED can be virtually eliminated. The output photodiode PD2 produces a photocurrent that is linearly related to the light output of the LED. The close matching of the photodiodes and advanced design of the package ensure the high linearity and stable gain characteristics of the optocoupler.

The HCNR200/201 can be used to isolate analog signals in a wide variety of applications that require good stability, linearity, bandwidth and low cost. The HCNR200/201 is very flexible and, by appropriate design of the application circuit, is capable of operating in many different modes, including: unipolar/ bipolar, ac/dc and inverting/ noninverting. The HCNR200/201 is an excellent solution for many analog isolation problems.

In the above circuit set the VR3 to obtain your desired voltage according to the thermocouple output gained .

Source :

1. Complete circuit of Low Cost (8-Channel) Thermocouple Signal Conditioning With Analog Multiplexer and Analog Optocoupler.
2. Datasheet ADG507A
3. Datasheet AD595
4. Datasheet INA126
5. Datasheet HCNR201
6. Thermacouple Singnal Conditioning PCB (Bottom Track).zip
7. Thermacouple Singnal Conditioning PCB (Solder Mask).zip
8. Thermacouple Singnal Conditioning PCB (TOP Legend).zip

The author is not responsible for any risk caused by this circuit. Refer all to the datasheet.

Circuit Cellar November 2010

2011-01-17T14:10:00.002+07:00

Circuit Cellar specializes in creative solutions, unique applications and useful design techniques for hands-on designers and developers. Circuit Cellar - is the magazine for computer applications. Click Here to Download

Circuit Cellar Februari 2010

2010-02-06T10:42:00.001+07:00

Click Here to download circuit cellar February 2010

Circuit Cellar Januari 2010

2010-02-06T10:23:00.002+07:00

Click Here To Download Circuit Cellar Januari 2010

Serial Device Tester

2009-09-09T10:24:00.002+07:00

The Serial Device Test Utility is designed to assist in analyzing the communicationbetween a PC and a device connected over the serial port. The application has a number of features to make this process relatively easy. Some of the features that are included are a fully configurable COM port interface, the ability to program constant wrappers (header/footer) around the serial port data, the ability to send data using either ASCII text, decimal values for each byt, or hexadecimal values for each byte, inbound data is decoded into both standard ASCII text and hexadecimal byte values, and the ability to log the data to a file in either HTML or plain text format.

The ASCII window for the inbound data has modified the data slightly -- when there is a carriage return or line feed in the data string, those values have been replaced with a "." in order to keep the ASCII window in sync with the Hex window. This utility has been very useful in debugging communications between remote devices and the computer when for whatever reason the actual data being sent does not agree with the documentation or the documentationis unclear on the exact byte sequence being sent or received. One of the most common areas of confusion that this will clear up immediately is what the end of a line truly is -- whether or not it is a carraige return, a line feed, or both (and if both what order they are actually sent).

Features that are currently under development for the next couple of releases include: The ability to pre-program a variety of commonly used commands that will be sent upoun selection, the ability to code automatic responses which wil be useful in situations where Acks or an equivalent response are required, inclusion of CRC and checksum capabilities, file transfer capabilites, and others still to be determined.

Click here to download Serial Device Tester

The LabVIEW Style Book (National Instruments Virtual Instrumentation Series)

2009-09-05T15:20:00.007+07:00

Drawing on the experiences of a world-class LabVIEW development organization, The LabVIEW Style Book is the definitive guide to best practices in LabVIEW development.

Leading LabVIEW development manager Peter A. Blume presents practical guidelines or "rules" for optimizing every facet of your applications: ease of use, efficiency, readability, simplicity, performance, maintainability, and robustness. Blume explains each style rule thoroughly, presenting realistic examples and illustrations. He even presents "nonconforming" examples that show what not to do-and why not.

Coverage includes

* Significance of style: How good style improves quality and actually saves time over the full project life cycle
* Before you code: Configuring your LabVIEW environment, and organizing your files on disk and in the LabVIEW project
* LabVIEW project specifications: A specialized standard for specifying LabVIEW application requirements
* Efficient VI layout and development: front panel, block diagram, icons, and connectors
* Data structures: Choosing data types, efficient use of arrays and clusters, and special considerations with nested data structures
* Error handling strategies: Trapping and reporting errors for robust and reliable applications
* Design patterns: Standard VI architectures and application frameworks that promote good style
* Documentation: Essential rules for source code documentation and streamlining the process
* Code reviews: Enforcing a style convention using a checklist, the LabVIEW VI Analyzer Toolkit, and peer reviews
* Appendixes: Convenient glossary and style rules summary

This book will be indispensable to anyone who wants to develop or maintain quality LabVIEW applications: developers, managers, and end users alike. Additionally, it will also be valuable to those preparing for NI's Certified LabVIEW Developer or Certified LabVIEW Architect exams, which contain significant content on development style.

Foreword by Darren Nattinger
Preface
Acknowledgments
About the Author
Chapter 1 The Significance of Style
Chapter 2 Prepare for Good Style
Chapter 3 Front Panel Style
Chapter 4 Block Diagram
Chapter 5 Icon and Connector
Chapter 6 Data Structures
Chapter 7 Error Handling
Chapter 8 Design Patterns
Chapter 9 Documentation
Chapter 10 Code Reviews
Appendix A Glossary
Appendix B Style Rules Summary
Index

About the Author

Peter Blume is the founder and president of Bloomy Controls, Inc., a National Instruments Select Integration Partner that specializes in LabVIEW-based systems development. Since LabVIEW Version 2.5, Blume and his staff of engineers have solved more than a thousand industrial applications for customers throughout the northeastern United States. To promote consistent quality among multiple developers in multiple offices, Blume established and evolved the company's LabVIEW development practices.

Blume has written and presented multiple LabVIEW style-related presentations, including Bloomy Controls' Professional LabVIEW Development Guidelines at NIWeek 2002 and Five Techniques for Better LabVIEW Code at NIWeek 2003. He also has published technical articles in various trade publications, including Test & Measurement World, Evaluation Engineering, Electronic Design, and Desktop Engineering.

Blume holds a Bachelor of Science degree in electrical engineering from the University of Connecticut. He is a National Instruments Certified LabVIEW Developer and Certified Professional Instructor. The company has offices in Connecticut, Massachusetts, and New Jersey. For more information, visit www.bloomy.com.

Readers who want to contact Blume regarding style-related suggestions, questions, or comments may do so at the following email address: lvstyle@bloomy.com . Readers interested in contracting Bloomy Controls for a LabVIEW development project should call us directly or contact us through our website at www.bloomy.com/quote.

Click here to download this ebook

Password : www.freebookspot.com

AVR Blips

2009-09-02T08:12:00.003+07:00

Thanks to: stevech@san.rr.com childressS@gmail.com

BLIPS is a graphical user interface and command line MS Windows program that loads programs and data into an Atmel AVR microprocessor’s flash and EEPROM memories. BLIPS transfers this data from a PC via either a serial port or a LAN/WAN connection (IP) to an Ethernet/WiFi to serial bridge – such as the Lantronix Xport or WiPort, or equivalent device. The AVR-side bootloader can be the sample provided in source code form with BLIPS or any that meets the Atmel AVR- 109 protocol.

Version 3 of BLIPS adds an optional command line interface to the graphical user interface in prior versions. This permits BLIPS to be called from scripts and batch files, with file and action parameters, and return a success status. The batch mode support for commercial for-profit endusers is controlled by a usage key. A sample command line batch file is:

blips progf -d atmega8 -p com1 -b 57600 "Flash file1.hex"
echo blips exit status = %errorlevel%

Click here to download more about AVR Blips

Notepad ++

2009-08-31T12:48:00.002+07:00

Notepad++ is a free (as in "free speech" and also as in "free beer") source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment, its use is governed by GPL License.

Based on a powerful editing component Scintilla, Notepad++ is written in C++ and uses pure Win32 API and STL which ensures a higher execution speed and smaller program size. By optimizing as many routines as possible without losing user friendliness, Notepad++ is trying to reduce the world carbon dioxide emissions. When using less CPU power, the PC can throttle down and reduce power consumption, resulting in a greener environment.

More about Notepad ++ click here

Frequency to Voltage Converter Circuit

2009-08-26T16:35:00.006+07:00

This circuit good working in the frequency range 0-850 Hz. You can change the value of R8 and C1 in order to get the various frequency range.

PIC18F4550 Module Trainer Board

2009-08-26T08:18:00.015+07:00

This site presents a simple didactical microcontroller modules designed for teaching of microcontroller systems, digital signal processing, and system programming.

Full documentation (schematic diagram and pcb design) is provided, and you are free to duplicate the modules. However, if you are going to use THESE schematic or PCB files to build and distribute the modules, than you should include the information about the original source and about the availability of the documentation.

PIC18F4550 module Parameters:

1. Clock frequency up to 48MHz (12 MIPS) with oscilator working at 8 MHz
2. Memory: 2KB RAM, 256 B EEPROM, 32KB code (FLASH)
3. USB 2.0 Interface - Low Speed & Full Speed
4. 10-bit ADC (7 channels available for user)
5. 2 analogue comparators
6. 4 timers and 2 PWM/CCP modules (one extended)
7. Synchronous/asynchronous serial interface (EUSART)
8. Synchronous serial interface: SPI/I2C
9. Parallel SPP port - for direct transfer of data over USB

This module is based on the PIC18F4550 microcontroller. It offers the direct USB connectivity. Available documentation includes the schematic diagram as PDF, sources of the schematic diagram in the gschem format, and the PCB layout in the free PCB program format.

ALL Material Download

Source : http://www.ise.pw.edu.pl

The NanoVM - Java for the AVR

2009-07-05T21:54:00.003+07:00

The NanoVM is a java virtual machine for the Atmel AVR ATmega8 CPU, the member of the AVR CPU family used e.g. in the DLR Asuro robot, manufactured by AREXX engineering. With the NanoVM, the Asuro can be programmed in the popular Java language using the standard Sun JDK. The NanoVM and its tools are distributed under the GPL and can be used on other AVR based systems as well.

The NanoVM for Asuro replaces the original firmware of the Asuro with a Java virtual machine capable of running a subset of the virtual machine command set. This enables e.g. the Asuro to interpret java bytecode and to run simple java programs like e.g. this one.

The NanoVM is a very resource aware implementation of the java vm. The Asuro version including a boot loader and several native classes fit into the 8kBytes flash rom of the Asuros AVR ATmega8 CPU. The complete 512 Byte EEPROM space of the CPU are available as Java program space and 75% of the 1 kByte RAM space are available to the running Java program.

More information about The NanoVM - Java for the AVR click here

Displaying SubVIs as Expandable Nodes [LabVIEW Tutorial]

2009-07-05T21:08:00.005+07:00

SubVIs may be viewed as either icons or expandable nodes. Express VIs are viewed as expandable nodes, by default. To view a subVI as an expandable node, right-click on it and uncheck the View As Icon option by selecting it from the pop-up menu, as shown in Figure 71. This will cause the subVI's appearance to change, such that its icon is surrounded by a yellow background, as shown in Figure 72.

Figure 71. SubVI with View As Icon setting enabled, as also indicated in its visible pop-up menu

Figure 72. SubVI with View As Icon setting disabled, appearing as an expandable node

We can resize the subVI vertically, which causes inputs and outputs to appear below the subVI's icon, as shown in Figure 73. Note that inputs and outputs made available are no longer available to the left and right of the subVI's icon.

Figure 73. Resizing (expanding) a subVI configured as an expandable node

You can also show and hide inputs and outputs from the subVI's pop-up menu, using the Select Input/Output submenu to change an input/output, Insert Input/Output to insert a new input/output, and Remove Input/Output to remove an input/output (see Figure 74).

Figure 74. Selecting the visible inputs and outputs of a subVI configured as an expandable, from its pop-up menu

Exploit The SoundCard as Oscilloscope

2009-06-25T18:34:00.005+07:00

Thanks to Konstantin Zeldovich

Oscilloscope for Windows version 2.51 (Oscilloscope 2.51) is an application showing how home PC peripherials, such as a sound card, can be used in an unconventional way, emulating industrial ADC hardware. The Oscilloscope provides a complete functionality of a "standalone" scope in a familiar Windows ennvironment.

The Oscilloscope allows you, for example:
- to study in real time any signal envelope,
- to measure frequencies
- to study realtime signal spectra,
- to plot Lissajous patterns.
- to measure a cross-correlation coefficient of two signals
(In general, to do most things you can do with an oscilloscope and a spectrum analyzer).

Not surprisingly, the Oscilloscope has several drawbacks too:
- non-calibrated amplitude level (hard to use as digital multimeter),
- relatively low bandwidth (20 Hz - 20 kHz),
- possibility of damage of a PC when connecting to an unknown signal source. (See Precautions ).

Specifications:
Dual trace digital storage oscilloscope with realtime spectrum analyzer and correlometer.
Buffer length: 52 ms
Bandwidth: 20 Hz - 20 kHz max
Input level: about 2 VAC, limited by sound card capabilities
Display refresh: ca. 6 fps
Data export: disk file or Windows clipboard, text format

Click here to download the oscilloscope software

USB Sniffer With SnoopyPro

2009-06-23T15:25:00.003+07:00

SnoopyPro is a tool for advanced USB programmers. It allows you to record each URB sent to and received from a USB device. This traces can be saved, loaded, edited, printed and combined into new traces.

WARNING: You might damage your system with this tool. Don't use it if you don't know what you're doing!!!! We're not responsible for anything that happens to you, your system, your devices, your marriage, etc. etc.

SUPPORTED OPERATING SYSTEMS:

Tested by the authors on Windows 98, Windows 2000, Windows XP

INSTALLATION/USE:

1. Run SnoopyPro.exe from whereever you have saved it.
2. Open up the USB devices window with F2.
3. Choose 'Unpack Drivers' from the 'File' menu.
4. Choose 'Install Service' from the 'File' menu.
5. Locate the device you want to sniff.
6. Right-click on it and choose 'Install and Restart'.
7. Wait for the magic to happen...

Click Here To Download SnoopyPro

The Toolbar in LabVIEW

2009-06-21T09:08:00.016+07:00

The Toolbar, located at the top of LabVIEW windows, contains buttons you will use to control the execution of your VI, as well as text configuration options and commands to control the alignment and distribution of objects (see Figure 59). You'll notice that the Toolbar has a few more options in the block diagram than in the front panel, and that a few editing-related options disappear when you run your VI. If you're not sure what a button does, hold the cursor over it until a tip strip appears, describing its function.

Figure 59. Toolbar

Run Button

Run Button (Active)

Run Button (Broken)

The Run button, which looks like an arrow, starts VI execution when you click on it. It changes appearance to active when a VI is actually running. When a VI won't compile, the run button appears broken.

Continuous Run Button

The Continuous Run button causes the VI to execute over and over until you hit the stop button. It's kind of like a GOTO statement (sort of a "programming no-no"), so use it sparingly.

Abort Button

The Abort button, easily recognizable because it looks like a tiny stop sign, becomes active when a VI begins to execute; otherwise, the Abort button is grayed out. You can click on this button to halt the VI.
Using the Abort button is like pulling the power cord on your computer. Your program will stop immediately rather than coming to a graceful end, and data integrity can be lost this way. You should always code a more appropriate stopping mechanism into your program, as we will demonstrate later.

Pause Button

The Pause button pauses the VI so that you can use single-step debugging options such as step into, step over, and step out. Hit the Pause button again to continue execution.

Step Into Button

Step Over Button

Step Out Button

The single-step buttonsStep Into, Step Over, and Step Outforce your VI to execute one step at a time so you can troubleshoot.

Execution Highlight Button

The Execution Highlight button causes the VI to highlight the flow of data as it passes through the diagram. When execution highlight is on, you can see intermediate data values in your block diagram that would not otherwise appear.

Retain Wire Values

The Retain Wire Values button causes the VI's wires to store the value that flowed through them the last time the VI executed. This is very useful for debugging. You can view the value stored in a wire by placing a probe on the wire. The probe value will be set to the value stored in the wire.

Warning Button

The Warning button appears if you have configured your VI to show warnings and you have any warnings outstanding. You can list the warnings by clicking on the button. A warning is not an error; it just alerts you that you are doing something you may not have intended (for example, if there are objects on the block diagram that are hidden behind other objects and cannot be seen).

Comm Sniffer (From Knightsoft.net)

2009-06-20T10:45:00.005+07:00

CommSniffer is a valuable tool for technicians, engineers and software developers designing/debugging serial port related projects, it is an advanced COM/RS232 Serial port data viewer / analyzer. View and send (all 256) ASCII/Binary data. Main features include:

Supports COM1 to COM16.
Baud rates from 110 to 115200.
Export transactions session to an ASCII file.
Designed for ease of use.
Ultra fast display rate.
Runs in Windows 9X/2000/XP.
Capture/send data to/from serial port.
Built in data converter ASCII/Binary/Hex.
Built in search.

and more...

Click here to download Comm Sniffer "FREE..."

Pic Baud Rate Calculator V2.1 (208Kb zip Win32 App)

2009-06-20T09:54:00.002+07:00

PIC Baud Calculator - a FREE utility to calculate the SPBRG value for the PIC processors with on board Uart. Simply enter the Clock speed and the desired Baud rate and hit calculate. The SPBRG value is shown for both BRG High and Low, including the difference error. On some older PIC uarts, the BRG High setting causes intermittent UART errors.

V2.1 now supports systems that require 'commas' instead of 'points' in floating point numbers.

his utility is provided FREE of charge and as such comes with no technical support or guarantee! by downloading it you agree to these terms. If you are unsure of the validity of the output from this utility, don't use it. :)

Click here to download PIC Baud Calculator

RTU and CPU Used in SCADA and Benefits Using SCADA System

2009-06-19T13:36:00.004+07:00

Remote terminal units

An RTU (sometimes referred to as a remote telemetry unit) as the title implies, is a standalone data acquisition and control unit, generally microprocessor based, which monitors and controls equipment at some remote location from the central station. Its primary task is to control and acquire data from process equipment at the remote location and to transfer this data back to a central station. It generally also has the facility for having its configuration and control programs dynamically downloaded from some central station. There is also a facility to be configured locally by some RTU programming unit. Although traditionally the RTU communicates back to some central station, it is also possible to communicate on a peer-to-peer basis with other RTUs. The RTU can also act as a relay station (sometimes referred to as a store and forward station) to another RTU, which may not be accessible from the central station.

Small sized RTUs generally have less than 10 to 20 analog and digital signals, medium sized RTUs have 100 digital and 30 to 40 analog inputs. RTUs, having a capacity greater than this can be classified as large.

A typical RTU configuration is shown in Figure below:

A short discussion follows on the individual hardware components. Typical RTU hardware modules include:
• Control processor and associated memory
• Analog inputs
• Analog outputs
• Counter inputs
• Digital inputs
• Digital outputs
• Communication interface(s)
• Power supply
• RTU rack and enclosure

Control processor (or CPU)

This is generally microprocessor based (16 or 32 bit) e.g. 68302 or 80386. Total memory capacity of 256 kByte (expandable to 4 Mbytes) broken into three types:
1 EPROM (or battery backed RAM) = 256 kByte
2 RAM = 640 kByte
3 Electrically erasable memory (flash or EEPROM) = 128 kByte

A mathematical processor is a useful addition for any complex mathematical calculations. This is sometimes referred to as a coprocessor.

Communication ports – typically two or three ports either RS-232/RS-422/RS-485 for:
• Interface to diagnostics terminal
• Interface to operator station
• Communications link to central site (e.g. by modem)

Diagnostic LEDs provided on the control unit ease troubleshooting and diagnosis of problems (such as CPU failure/failure of I/O module etc).

Another component, which is provided with varying levels of accuracy, is a real-time clock with full calendar (including leap year support). The clock should be updated even during power off periods. The real-time clock is useful for accurate time stamping of events.

A watchdog timer is also required to provide a check that the RTU program is regularly executing. The RTU program regularly resets the watchdog time. If this is not done within a certain time-out period the watchdog timer flags an error condition (and can reset the CPU).

Considerations and benefits of SCADA system

Typical considerations when putting a SCADA system together are:
• Overall control requirements
• Sequence logic
• Analog loop control
• Ratio and number of analog to digital points
• Speed of control and data acquisition
• Master/operator control stations
• Type of displays required
• Historical archiving requirements
• System consideration
• Reliability/availability
• Speed of communications/update time/system scan rates
• System redundancy
• Expansion capability
• Application software and modeling

Obviously, a SCADA system’s initial cost has to be justified. A few typical reasons for implementing a SCADA system are:
• Improved operation of the plant or process resulting in savings due to optimization of the system
• Increased productivity of the personnel
• Improved safety of the system due to better information and improved control
• Protection of the plant equipment
• Safeguarding the environment from a failure of the system
• Improved energy savings due to optimization of the plant
• Improved and quicker receipt of data so that clients can be invoiced more quickly and accurately
• Government regulations for safety and metering of gas (for royalties & tax etc)

Electric Circuits,7th Edtion

2009-06-19T11:30:00.002+07:00

Electric Circuits, Seventh Edition features a redesigned art program, a new four-color format, and 75% new or revised problems throughout. In the midst of these changes, the book retains the goals that have made it a best-seller: 1) To build an understanding of concepts and ideas explicitly in terms of previous learning; 2) To emphasize the relationship between conceptual understanding and problem solving approaches; 3) To provide readers with a strong foundation of engineering practices. Chapter topics include Circuit Variables; Circuit Elements; Simple Resistive Circuits; Techniques of Circuit Analysis; The Operational Amplifier; Inductors, Capacitors, and Mutual Inductance; Response of First-Order RL and RC Circuits; Natural and Step Responses of RLC Circuits; Sinusoidal Steady-State Analysis; and more. For anyone interested in circuit analysis.

Click Here To Download This Ebook

SMT USB AVR Programmer With ATTINY2313SO

2009-06-18T18:03:00.014+07:00

Thanks to : Ayman El-Khashab, phd, pe

Here is the first iteration of the AVR µISP programmer. This is based on the usbtinyisp from adafruit, that was in turn based on Dick Streefland's USBTiny and the USB stack at www.obdev.at. but smaller and with all SMT parts except for the 10 and 6 pin headers.

I chose to spin my own design since I wanted to use it in a few different modes.First, I wanted to use a standard ISP cable. Second, I wanted to be able to insert pins from the programmer into boards without requiring the ISP header pins populated. Third, I wanted the capability to attach QFP and SOIC clips. And finally, by placing a female connector on the bottom of the programmer, it is possible to place the entire programmer atop a board header.

There are only a few differences in this design

100 Ω series resistors instead of 1500 Ω
Mini USB connector
Blue LED instead of green
Pin mapping of the AVR is slightly different

The entire board is 46mm x 20mm (about 1.8" by 0.8"). The hex code is available below, but if you want to build the code yourself, be certain to use GCC 3.x version. The 4.x versions do not do well with the AVR code size and this program is extremely tight in the ATTiny2313. Secondly, you will need a way to load the initial firmware into the AVR. I used my old standby, the SP12 that I have used for several years.

Since it is based on other designs, this one works with the avrdude programmer as well. Unfortunately the USB organization has come down on the people parcelling out PIDs, so you may have a difficult time getting another one if you so desire.

In addition to using this for programming AVRs, it may be used as a generic SPI controller or JTAG interface. It does not have enough pins for TMS, TCK, TDI, TRST, and TDO. However, many parts (and every Xilinx part I've ever used) do not have a TRST so with just the 3 outputs and 1 input it is possible to program Xilinx FPGAs and CPLDs. You may need a pullup on TDO. Then you can use the playxsvf program to sent a bitstream to the part. I currently use a variant of this for programming the ps3toothfairy devices. I implemented the same thing with the SP12, but it is parallel only and support for parallel ports is dwindling.

Modifying the code

If you decide to make some design changes and spin your own board, you'll need to edit the c code and the header file. The pins are well labeled except for a couple of writes to PORTD. Just search for PORTD in the spi.c code and update for your particular configuration. It is wise to read through the USB headers as well as the usbtiny.h file to understand what you can and cannot change in your design.

If you build the code and it is too large for the device, you have a couple of options. If it is a few bytes off, you can try reducing the string size in usbtiny.h. If it is much too large, you probably have something wrong in your compile or build settings. Check the makefile and be certain you aren't building with the gcc 4.x toolchain.

You can operate the device with avrdude. You may need to add in usb support depending on your platform (it is needed for cygwin).

Anyway, enjoy and thanks to the folks that made previous designs possible.

Build it

Here are pictures of the schematic and gerbers. Download the design below. We may make some available for purchase (especially since you need some method to initially program the micro). The build is not difficult with an iron, but it is likely easier with a toaster oven or hotplate reflow. (I've built a couple all with an iron in a couple of minutes). Click the images to get a larger view. The crystal goes either direction since the pins are at the corners.

Here is the BOM. None of the parts are particularly critical, other than you need to make sure to get the proper footprint.

Downloads

Note that updates were made to the Eagle files after the prototype and I haven't fabbed any from this design yet. It should work (as it was just moving some traces), but as with anything you download, trust-but-verify.

Firmware Source & Hex Code
Eagle Sch & PCB

License

The USBtiny software is licensed under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the license, or (at your option) any later version. A copy of the GPL version 2 license can be found in the file COPYING.

Analog Electronics with LabVIEW

2009-06-18T07:08:00.002+07:00

From the Back Cover

The hands-on, simulation-based introduction to analog electronics.

Analog Electronics with LabVIEW is the first comprehensive introduction to analog electronics that makes full use of computer simulation. Kenneth L. Ashley introduces analog electronics through a series of theory/project sections, in which theoretical presentations correlate directly with circuit measurement and analysis projects. The results of experiments are used to extract device model parameters used in subsequent electronic circuit analysis, providing a significant enhancement in the understanding of modern, computer-based electronic-circuit simulation. Readers will master not only the fundamentals of analog electronics, but also data acquisition and circuit simulation with LabVIEW, basic circuit-solution computation with Mathcad, and circuit simulation with Cadence Schematics or Capture. Coverage includes:

* Elementary analog circuit analysis, including the resistor voltage divider and MOSFET DC gate voltage, MOSFET drain current-source equivalent, amplifier frequency response, and more
* Fundamentals of transistors and voltage amplification
* Characterization of MOS transistors for circuit simulation
* Common-source amplifiers, MOSFET source-follower buffer stage, differential amplifier stage, and MOSFET current sources
* Operational amplifiers: resistor negative feedback approaches and capacitor-based applications
* Development of a Basic CMOS Operational Amplifier
* LabVIEW tutorial with emphasis on analog electronics, the discrete nature of compute data acquisition, and LabVIEW measurement VIs such as the autoranging DC voltmeter
* Characterization of the BJT for circuit simulation including linear modeling
* BJT NPN common-emitter amplifier, including emitter degeneration and current-source PNP load with emitter degeneration

For those new to LabVIEW, the book also contains a complete introductory tutorial with emphasis relevant to analog-electronics applications.

The accompanying CD-ROM includes a complete copy of LabVIEW 6 Student Edition Software, along with all the LabVIEW, Mathcad, and Schematics (or Capture) files you need to perform the experiments and exercises in this book, plus samples of all project measurement and data files for measurement simulation.

Click Here to download Analog Electronics with LabVIEW

Password : www.freebookspot.com

Transformerless Power Supply

2009-06-17T08:42:00.004+07:00

Electric Shock Hazard. In the UK,the neutral wire is connected to earth at the power station. If you touch the "Live" wire, then depending on how well earthed you are, you form a conductive path between Live and Neutral. DO NOT TOUCH the output of this power supply. Whilst the output of this circuit sits innocently at 12V with respect to (wrt) the other terminal, it is also 12V above earth potential. Should a component fail then either terminal will become a potential shock hazard.

If you are not experienced in dealing with it, then leave this project alone.Although Mains equipment can itself consume a lot of current, the circuits we build to control it, usually only require a few milliamps. Yet the low voltage power supply is frequently the largest part of the construction and a sizeable portion of the cost.

This circuit will supply up to about 20ma at 12 volts. It uses capacitive reactance instead of resistance; and it doesn't generate very much heat.The circuit draws about 30ma AC. Always use a fuse and/or a fusible resistor to be on the safe side. The values given are only a guide. There should be more than enough power available for timers, light operated switches, temperature controllers etc, provided that you use an optical isolator as your circuit's output device. (E.g. MOC 3010/3020) If a relay is unavoidable, use one with a mains voltage coil and switch the coil using the optical isolator.C1 should be of the 'suppressor type'; made to be connected directly across the incoming Mains Supply. They are generally covered with the logos of several different Safety Standards Authorities. If you need more current, use a larger value capacitor; or put two in parallel; but be careful of what you are doing to the Watts. The low voltage 'AC' is supplied by ZD1 and ZD2.

The bridge rectifier can be any of the small 'Round', 'In-line', or 'DIL' types; or you could use four separate diodes. If you want to, you can replace R2 and ZD3 with a 78 Series regulator. The full sized ones will work; but if space is tight, there are some small 100ma versions available in TO 92 type cases. They look like a BC 547. It is also worth noting that many small circuits will work with an unregulated supply. You can, of course, alter any or all of the Zenner diodes in order to produce a different output voltage. As for the mains voltage, the suggestion regarding the 110v version is just that, a suggestion. I haven't built it, so be prepared to experiment a little.

I get a lot of emails asking if this power supply can be modified to provide currents of anything up to 50 amps. It cannot. The circuit was designed to provide a cheap compact power supply for Cmos logic circuits that require only a few milliamps. The logic circuits were then used to control mains equipment (fans, lights, heaters etc.) through an optically isolated triac. If more than 20mA is required it is possible to increase C1 to 0.68uF or 1uF and thus obtain a current of up to about 40mA. But 'suppressor type' capacitors are relatively big and more expensive than regular capacitors; and increasing the current means that higher wattage resistors and zener diodes are required. If you try to produce more than about 40mA the circuit will no longer be cheap and compact, and it simply makes more sense to use a transformer.

I.C. Datasheets : 74xxx - Set 02

2009-06-07T09:54:00.001+07:00

Click here to download I.C. Datasheets : 74xxx - Set 02

I.C. Datasheets : 74xxx - Set 01

2009-06-07T09:47:00.001+07:00

Click here to download I.C. Datasheets : 74xxx - Set 01

I.C. Datasheets : 4000

2009-06-07T09:45:00.002+07:00

Click here to download I.C. Datasheets : 4000

I.C. Datasheets : Analog - Set 02

2009-06-07T09:43:00.002+07:00

Click here to download I.C. Datasheets : Analog - Set 02

I.C. Datasheets : Analog- Set 01

2009-06-07T09:40:00.001+07:00

Click here to download I.C. Datasheets : Analog- Set 01

I.C. Datasheets : General Purpose

2009-06-07T09:37:00.002+07:00

Click here to download this IC Datasheet : General Purpose

AVR Simulator IDE

2009-06-06T16:04:00.005+07:00

AVR Simulator IDE is powerful application that supplies AVR developers with user-friendly graphical development environment for Windows with integrated simulator (emulator), BASIC compiler, assembler, disassembler and debugger.

The main application window shows all AVR microcontroller internal registers status (general purpose working and I/O registers, internal data SRAM and program counter), mnemonics of the last executed instruction, mnemonics of the next instruction that will be executed, clock cycles and instructions counter and real time duration of the
simulation.

Click here to download AVR Simulator IDE

PIC Simulator IDE for PIC 16F Family

2009-06-05T21:18:00.004+07:00

PIC Simulator IDE is powerful application that supplies PIC developers with user-friendly graphical development environment for Windows with integrated simulator (emulator), BASIC compiler, assembler, disassembler and debugger.

The main application window shows all PIC microcontroller internal registers status, mnemonics of the last executed instruction, mnemonics of the next instruction that will be executed, clock cycles and instructions counter and real time duration of the simulation.

Click here to download PIC Simulator IDE for PIC 16F Family

Floating Palettes in LabVIEW

2009-05-31T20:02:00.027+07:00

LabVIEW has three often-used floating palettes that you can place in a convenient spot on your screen: the Tools palette, the Controls palette, and the Functions palette. You can move them around by clicking on their title bar and dragging. Close them just like you would close any window in your operating system. If you decide you want them back, select the palette you want from the View menufor example, View>>Tools Palette opens the Tools palette.

Controls and Functions Palettes

You will be using the Controls palette a lot, because that's where you select the controls and indicators that you want on your front panel. You will probably use the Functions palette even more often, because it contains the functions and structures used to build a VI.

The Controls and Functions palettes are unique in several ways. Most importantly, the Controls palette is only visible when the front panel window is active, and the Functions palette is only visible when the block diagram window is active. Both palettes have subpalettes containing the objects you need to access. As you pass the cursor over each subpalette button in the Controls and Functions palettes, you will notice that the subpalette's name appears in a tip strip beneath the mouse pointer (see Figure 40).

Figure 40. Controls palette

To select an object in the subpalette, click the mouse button over the object, and then click on the front panel or block diagram to place it where you want it.

Palette Item Categories

At the top level of the palettes are several "Categories," such as Modern, System, Classic, Express, Addons, Favorites, and others. You can expand and close these categories, by clicking on them, to navigate the tree of items and subcategories that are available within the palette.

One great category is Favorites (this is only present on the Functions palette, not the Controls palette). You can use this to group together items that you access frequently. When you find a function, structure, VI, or subpalette that you really like, right-click on the object and select Add Item to Favorites from the shortcut menu. This will add the object to the Favorites category, for quick and easy access.

Showing and Hiding Palette Categories

You can choose which categories you want to appear on the Controls or Functions palettes by pressing the View button and then selecting categories from the Always Visible Categories submenu. If you want all of the categories to be visible, select the Show All Categories option from the Always Visible Categories submenu (see Figure 41).

Figure 41. The Always Visible Categories

submenu of the palette View button

If a category is not selected in the Always Visible Categories, then you will not normally see it in the palette. However, you can temporarily display all of the categories by clicking on the double "down" arrows at the very bottom of the palette, as shown in Figure 42. You can hide those categories again by clicking on the double "up" arrows at the very bottom of the palette, as shown in Figure 43.

Figure 42. Functions palette with only

the "always visible" categories visible

Figure 43. Functions palette with all categories visible

Reordering Palette Categories

You can reorder the palette categories by right-clicking on them and choosing Move this Category Up, Move this Category Down, or Move to Top (Expand by Default). Additionally, you can drag and drop the categories within the list by clicking on the two vertical grab-bars (||) to the left of the category text.

Palette View Formats

The way that you navigate the palettes can be changed by choosing a different palette View Format. Pressing the View button at the top of a palette will open a menu. In the View This Palette As submenu, you can choose from six different View Formats, as shown in Figure 44.

Figure 44. The View This Palette As submenu

of the palette View button menu showing the

currently selected checked palette view format

Category (Standard) is the default View Format, and the one shown throughout this tutorial.

Category (Icons and Text), shown in Figure 45, is similar to Category (Standard), except that each item's name appears directly beneath its icon.

Figure 45. "Category (Icons and Text)" palette view format

Icons, shown in Figure 46, is the format that most are familiar with from previous versions of LabVIEW. Each subpalette and item is represented by an icon. When you mouse-over an item, its name appears at the top of the palette.

Figure 46. "Icons" palette view format

Icons and Text, shown in Figure 47, is similar to Icons, except that each item's name appears directly beneath its icon.

Figure 47. "Icons and Text" palette view format

Text, shown in Figure 48, is minimal. It behaves like the Icons and Icons and Text formats, where clicking on a subpalette navigates down into that subpalette. Subpalettes are represented by folders with names, and items are represented by their name.

Figure 48. "Text" palette view format

Tree, shown in Figure 49, is also minimal, having only folder icons and item names. However, it behaves more like the Category formats, having a tree hierarchy.

Figure 49. "Tree" palette view format

The "Icons," "Icons and Text," and "Text" palette view formats all have an "up" button (see Figure 50), which, when pressed, returns you to the previous ("owning") palettesince these view formats are not a tree view. You can search for a specific item in a palette by clicking on the spyglass icon (see Figure 50).

Figure 50. The buttons at the top of each palette are used for navigation and configuration options.

There is another way to navigate palettes that some people find a little easier. Instead of each subpalette replacing the current palette, you can pass through subpalettes in a hierarchical manner without them replacing their parent palettes. You can do this by right-clicking (Windows) or control-clicking (Mac OS X) the subpalette icons (see Figure 51).

Figure 51. A floating subpalette created by right-clicking on a subpalette icon

Note that some subpalettes have subpalettes containing more objects; these are denoted by a little triangle in the upper-right corner of the icon and a raised appearance (see Figure 52). We'll discuss specific subpalettes and their objects in the next chapter.

Figure 52. Functions palette with two levels of floating subpalettes visible

Comparison of the terms SCADA, DCS, PLC and smart instrument

2009-05-28T21:59:00.008+07:00

A. Scada System

A SCADA (or supervisory control and data acquisition) system means a system consisting of a number of remote terminal units (or RTUs) collecting field data connected back to a master station via a communications system. The master station displays the acquired data and also allows the operator to perform remote control tasks. The accurate and timely data (normally real-time) allows for optimization of the operation of the plant and process. A further benefit is more efficient, reliable and most importantly, safer operations. This all results in a lower cost of operation compared to earlier non-automated systems.

There is a fair degree of confusion between the definition of SCADA systems and process control system. SCADA has the connotation of remote or distant operation. The inevitable question is how far ‘remote’ is – typically this means over a distance such that the distance between the controlling location and the controlled location is such that direct-wire control is impractical (i.e. a communication link is a critical component of the system).

A successful SCADA installation depends on utilizing proven and reliable technology, with adequate and comprehensive training of all personnel in the operation of the system. There is a history of unsuccessful SCADA systems – contributing factors to these systems includes inadequate integration of the various components of the system, unnecessary complexity in the system, unreliable hardware and unproven software. Today hardware reliability is less of a problem, but the increasing software complexity is producing new challenges. It should be noted in passing that many operators judge a SCADA system not only by the smooth performance of the RTUs, communication links and the master station (all falling under the umbrella of SCADA system) but also the field devices (both transducers and control devices). The field devices however fall outside the scope of SCADA in this manual and will not be discussed further. A diagram of a typical SCADA system is given opposite.

On a more complex SCADA system there are essentially five levels or hierarchies:
• Field level instrumentation and control devices
• Marshalling terminals and RTUs
• Communications system
• The master station(s)
• The commercial data processing department computer system
The RTU provides an interface to the field analog and digital signals situated at each
remote site.
The communications system provides the pathway for communications between the
master station and the remote sites. This communication system can be radio, telephone line, microwave and possibly even satellite. Specific protocols and error detection philosophies are used for efficient and optimum transfer of data. The master station (and submasters) gather data from the various RTUs and generally provide an operator interface for display of information and control of the remote sites. In large telemetry systems, submaster sites gather information from remote sites and act as a relay back to the control master station.

SCADA technology has existed since the early sixties and there are now two other competing approaches possible – distributed control system (DCS) and programmable logic controller (PLC). In addition there has been a growing trend to use smart instruments as a key component in all these systems. Of course, in the real world, the designer will mix and match the four approaches to produce an effective system matching his/her application.

B. Distributed control system (DCS)

In a DCS, the data acquisition and control functions are performed by a number of distributed microprocessor-based units situated near to the devices being controlled or the instrument from which data is being gathered. DCS systems have evolved into systems providing very sophisticated analog (e.g. loop) control capability. A closely integrated set of operator interfaces (or man machine interfaces) is provided to allow for easy system configurations and operator control. The data highway is normally capable of fairly high speeds (typically 1 Mbps up to 10 Mbps).

C. Programmable logic controller (PLC)

Since the late 1970s, PLCs have replaced hardwired relays with a combination of ladder–logic software and solid state electronic input and output modules. They are often used in the implementation of a SCADA RTU as they offer a standard hardware solution, which is very economically priced.

Another device that should be mentioned for completeness is the smart instrument which both PLCs and DCS systems can interface to.

D. Smart instrument

Although this term is sometimes misused, it typically means an intelligent (microprocessor based) digital measuring sensor (such as a flow meter) with digital data communications provided to some diagnostic panel or computer based system.

This tutorial will henceforth consider DCS, PLC and smart instruments as variations or components of the basic SCADA concept.

Programming 8-bit PIC Microcontrollers in C: with Interactive Hardware Simulation

2009-05-25T20:19:00.000+07:00

Step-by-step, practical instruction on how to program PICs in C, with no prior experience necessary!

Product Description
PIC Microcontrollers are present in almost every new electronic application that is released from garage door openers to the iPhone. With the proliferation of this product more and more engineers and engineers-to-be (students) need to understand how to design, develop, and build with them. Martin Bates, best-selling author, has provided a step-by-step guide to programming these microcontrollers (MCUs) with the C programming language.

With no previous knowledge of C necessary to read this book, it is the perfect for entry into this world for engineers who have not worked with PICs, new professionals, students, and hobbyists. As MCUs become more complex C is the most popular language due to its ability to process advanced processes and multitasking. RTOSs, that is a need to know for engineers, is also discussed as more advanced MCUs require timing and organization of programming and implementation of multitasking. The book includes lots of source code, circuit schematics, and hardware block diagrams. Microchip's PICDEM Mechatronics board is used to detail the examples throughout the book.

* Focuses on the C programming language which is by far the most popular for microcontrollers (MCUs)
* Features Proteus VSMg the most complete microcontroller simulator on the market, along with CCS PCM C compiler, both are highly compatible with Microchip tools
* Extensive downloadable content including fully worked examples

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Introduction to Microcontrollers: Architecture, Programming, and Interfacing for the Motorola 68HC12

2009-05-25T20:06:00.005+07:00

Provides a comprehensive introductory text/ reference for electrical and computer engineers, students and even hobbyists who have little experience in high-level programming language. Discusses how a typical microcontroller executes assembler language instruction and addresses models on microprocessors.

Introduction to Microcontrollers is a comprehensive introductory text/reference for electrical and computer engineers, students, and even hobbyists who have little experience in a high-level programming language. The book helps them understand how a typical microcontroller executes assembly language instructions and addressing modes on microprocessors. The book shows how to program with C++ and compile assembly language statements. The book utilizes the new 16-bit microcontroller, the Motorola 68Hc12, as the primary example. This "chip" replaces the very popular 8-bit microcontroller, the 68Hc11, as the leading microprocessor for a wide variety of applications and as a core tool for teaching engineering students. This new microcontroller is expected to be popular in industry because of its low cost per unit, low power consumption, and high processing speed.

* First introductory level book on the Motorola 68HC12

* Teaches engineers how a computer executes instructions

* Shows how a high-level programming language converts to assembly language

* Teaches the reader how a microcontroller is interfaced to the outside world

* Uses hundreds of examples throughout the text

* Over 200 homework problems give the reader in-depth practice

* A CD-ROM with HiWare's professional C++ compiler is included with the book

* A complete summary chapter on other available microcontrollers

Click here to Download Introduction to Microcontrollers: Architecture, Programming, and Interfacing for the Motorola 68HC12

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SCADA (Hardware and Software)

2009-05-24T20:37:00.004+07:00

SCADA hardware

A SCADA system consists of a number of remote terminal units (RTUs) collecting field data and sending that data back to a master station, via a communication system. The master station displays the acquired data and allows the operator to perform remote control tasks.

The accurate and timely data allows for optimization of the plant operation and process. Other benefits include more efficient, reliable and most importantly, safer operations. This results in a lower cost of operation compared to earlier non-automated systems.

On a more complex SCADA system there are essentially five levels or hierarchies:
• Field level instrumentation and control devices
• Marshalling terminals and RTUs
• Communications system
• The master station(s)
• The commercial data processing department computer system

The RTU provides an interface to the field analog and digital sensors situated at each remote site.

The communications system provides the pathway for communication between the master station and the remote sites. This communication system can be wire, fiber optic, radio, telephone line, microwave and possibly even satellite. Specific protocols and error detection philosophies are used for efficient and optimum transfer of data.

The master station (or sub-masters) gather data from the various RTUs and generally provide an operator interface for display of information and control of the remote sites. In large telemetry systems, sub-master sites gather information from remote sites and act as a relay back to the control master station.

SCADA software

SCADA software can be divided into two types, proprietary or open. Companies develop proprietary software to communicate to their hardware. These systems are sold as ‘turn key’ solutions. The main problem with this system is the overwhelming reliance on the supplier of the system. Open software systems have gained popularity because of the interoperability they bring to the system. Interoperability is the ability to mix different manufacturers’ equipment on the same system.

Citect and WonderWare are just two of the open software packages available in the market for SCADA systems. Some packages are now including asset management integrated within the SCADA system. The typical components of a SCADA system are indicated in the next diagram.

Key features of SCADA software are:
• User interface
• Graphics displays
• Alarms
• Trends
• RTU (and PLC) interface
• Scalability
• Access to data
• Database
• Networking
• Fault tolerance and redundancy
• Client/server distributed processing

Introduction And Brief History of SCADA

2009-05-24T19:25:00.005+07:00

This manual is designed to provide a thorough understanding of the fundamental concepts and the practical issues of SCADA systems. Particular emphasis has been placed on the practical aspects of SCADA systems with a view to the future. Formulae and details that can be found in specialized manufacturer manuals have been purposely omitted in favor of concepts and definitions.

This information provides an introduction to the fundamental principles and terminology used in the field of SCADA. It is a summary of the main subjects to be covered throughout the manual.

SCADA (supervisory control and data acquisition) has been around as long as there have been control systems. The first ‘SCADA’ systems utilized data acquisition by means of panels of meters, lights and strip chart recorders. The operator manually operating various control knobs exercised supervisory control. These devices were and still are used to do supervisory control and data acquisition on plants, factories and power generating facilities. The following figure shows a sensor to panel system.

The sensor to panel type of SCADA system has the following advantages:

It is simple, no CPUs, RAM, ROM or software programming needed
The sensors are connected directly to the meters, switches and lights on the panel
It could be (in most circumstances) easy and cheap to add a simple device like a switch or indicator

The disadvantages of a direct panel to sensor system are:

The amount of wire becomes unmanageable after the installation of hundreds of sensors
The quantity and type of data are minimal and rudimentary
Installation of additional sensors becomes progressively harder as the system grows
Re-configuration of the system becomes extremely difficult
Simulation using real data is not possible
Storage of data is minimal and difficult to manage
No off site monitoring of data or alarms
Someone has to watch the dials and meters 24 hours a day

Fundamental principles of modern SCADA systems

In modern manufacturing and industrial processes, mining industries, public and private utilities, leisure and security industries telemetry is often needed to connect equipment and systems separated by large distances. This can range from a few meters to thousands of kilometers. Telemetry is used to send commands, programs and receives monitoring information from these remote locations.

SCADA refers to the combination of telemetry and data acquisition. SCADA encompasses the collecting of the information, transferring it back to the central site, carrying out any necessary analysis and control and then displaying that information on a number of operator screens or displays. The required control actions are then conveyed back to the process.

In the early days of data acquisition, relay logic was used to control production and plant systems. With the advent of the CPU and other electronic devices, manufacturers incorporated digital electronics into relay logic equipment. The PLC or programmable logic controller is still one of the most widely used control systems in industry. As need to monitor and control more devices in the plant grew, the PLCs were distributed and the systems became more intelligent and smaller in size. PLCs and DCS (distributed control systems) are used as shown below.

The advantages of the PLC / DCS SCADA system are:

The computer can record and store a very large amount of data
The data can be displayed in any way the user requires
Thousands of sensors over a wide area can be connected to the system
The operator can incorporate real data simulations into the system
Many types of data can be collected from the RTUs
The data can be viewed from anywhere, not just on site

The disadvantages are:

The system is more complicated than the sensor to panel type
Different operating skills are required, such as system analysts and programmer
With thousands of sensors there is still a lot of wire to deal with
The operator can see only as far as the PLC

As the requirement for smaller and smarter systems grew, sensors were designed with the intelligence of PLCs and DCSs. These devices are known as IEDs (intelligent electronic devices). The IEDs are connected on a fieldbus, such as Profibus, Devicenet or Foundation Fieldbus to the PC. They include enough intelligence to acquire data, communicate to other devices, and hold their part of the overall program. Each of these super smart sensors can have more than one sensor on-board. Typically, an IED could combine an analog input sensor, analog output, PID control, communication system and program memory in one device.

The advantages of the PC to IED fieldbus system are:

Minimal wiring is needed
The operator can see down to the sensor level
The data received from the device can include information such as serial numbers, model numbers, when it was installed and by whom
All devices are plug and play, so installation and replacement is easy
Smaller devices means less physical space for the data acquisition system

The disadvantages of a PC to IED system are:

More sophisticated system requires better trained employees
Sensor prices are higher (but this is offset somewhat by the lack of PLCs)
The IEDs rely more on the communication system

Alignment Grid & Pull-Down Menus in LabVIEW

2009-05-24T13:23:00.015+07:00

Alignment Grid

you probably noticed the grid lines on the VI's front panel and how the waveform chart and stop controls "snap" to the grid lines as you move them around with the mouse. This feature is very useful for keeping your front panel objects aligned. If you do not like this feature, you can turn it off in the LabVIEW Options dialog. (Figures 30 and 31 show a VI front panel with the alignment grid feature turned ON and OFF, respectively.) Open the options dialog by selecting Tools, Options. . . from the menu. Navigate to the Alignment Grid category. From here, you can choose to show or hide the grid lines and to enable or disable grid alignment. If you are not sure of your preference, leave the alignment grid onyou'll probably like it.

Figure 30. VI with alignment grid option ON

Figure 31. VI with alignment grid option OFF

Pull-Down Menus

Keep in mind that LabVIEW's capabilities are many and varied. This tutorial by no means provides an exhaustive list of all of LabVIEW's ins and outs (it would be several thousand pages long if that were the case); instead, we try to get you up to speed comfortably and give you an overview of what you can do. If you want to know everything there is to know about a subject, we'd recommend looking it up in one of LabVIEW's many manuals, attending a seminar, or going to ni.com/labview on the Web. Feel free to skim through this section and some of the subsequent ones, but remember that they're here if you need a reference.

LabVIEW has two main types of menus: pull-down and pop-up. You used some of them in the last activity, and you will use both extensively in all of your program development henceforth. Now you will learn more about what they can do. We'll cover pull-down menu items very briefly in this section. You might find it helpful to look through the menus on your computer as we explain them, and maybe experiment a little.

The menu bar at the top of a VI window contains several pull-down menus (in Mac OS X, the menu bar will be at the top of the screen, consistent with other Mac OS X applications). When you click on a menu bar item, a menu appears below the bar. The pull-down menus contain items common to many applications, such as Open, Save, Copy, and Paste, and many other functions particular to LabVIEW. We'll discuss some basic pull-down menu functions here. You'll learn more about the advanced capabilities later.

Many menus also list shortcut keyboard combinations for you to use if you choose. To use keyboard shortcuts, press the appropriate key in conjunction with the control key on PCs, the command key on Macs, and the meta key on Linux.

File Menu

Pull down the File menu , which contains commands common to many applications, such as Save and Print. You can also create new VIs or open existing ones from the File menu. In addition, you can show VI Properties information and development history from this menu.

Edit Menu

Take a look at the Edit menu (see Figure 33). It has some universal commands, like Undo, Cut, Copy, and Paste, that let you edit your window. You can also search for objects with the Find and Replace . . . command and remove bad wires from the block diagram.

Figure 33. Edit menu

View Menu

In the View menu (see Figure 34), you will see options for opening the Controls Palette, Functions Palette, and Tools Palette if you've closed them. You can also show the error list and see a VI's hierarchy. The Browse Relationships submenu contains features to simplify navigation among large sets of VIs, such as determining all of a VI's subVIs and where a VI is used as a subVI.

Project Menu

The Project menu (see Figure 35) allows you to open a LabVIEW project or create a new project, as well as operate on the project to which the active VI belongs. If the active VI does not belong to any LabVIEW project, only the Open Project and New Project menu items will be enabled.

Operate Menu

You can run or stop your program from the Operate menu (see Figure 36), although you'll usually use Toolbar buttons. You can also change a VI's default values, control "print and log at completion" features, and switch between run mode and edit mode.

Figure 36. Operate menu

Tools Menu

The Tools menu (see Figure 37) lets you access built-in and add-on tools and utilities that work with LabVIEW, such as the Measurement & Automation Explorer, where you configure your DAQ devices, or the Web Publishing Tool for creating HTML pages from LabVIEW. You can view and change the myriad of LabVIEW's Options

Figure 37. Tools menu

Window Menu

Pull down the Window menu (see Figure 38). Here you can toggle between the front panel and block diagram windows, "tile" both windows so you can see them at the same time, and switch between open VIs.

Figure 38. Window menu

Help Menu

You can show, hide, or lock the contents of the Context Help window using the Help menu (see Figure 39). You can also access LabVIEW's online reference information and view the About LabVIEW information window.

Figure 39. Help menu

PIC Microcontrollers, Second Edition: An Introduction to Microelectronics

2009-05-24T13:07:00.001+07:00

A comprehensive, highly illustrated introduction to microelectronic systems and the PIC microcontroller.

Product Description

The use of microcontroller based solutions to everyday design problems in electronics, is the most important development in the field since the introduction of the microprocessor itself. The PIC family is established as the number one microcontroller at an introductory level.

Assuming no prior knowledge of microprocessors, Martin Bates provides a comprehensive introduction to microprocessor systems and applications covering all the basic principles of microelectronics.

Using the latest Windows development software MPLAB, the author goes on to introduce microelectronic systems through the most popular PIC devices currently used for project work, both in schools and colleges, as well as undergraduate university courses. Students of introductory level microelectronics, including microprocessor / microcontroller systems courses, introductory embedded systems design and control electronics, will find this highly illustrated text covers all their requirements for working with the PIC.

Part A covers the essential principles, concentrating on a systems approach. The PIC itself is covered in Part B, step by step, leading to demonstration programmes using labels, subroutines, timer and interrupts. Part C then shows how applications may be developed using the latest Windows software, and some hardware prototyping methods.

The new edition is suitable for a range of students and PIC enthusiasts, from beginner to first and second year undergraduate level. In the UK, the book is of specific relevance to AVCE, as well as BTEC National and Higher National programmes in electronic engineering.

* A comprehensive introductory text in microelectronic systems, written round the leading chip for project work

* Uses the latest Windows development software, MPLAB, and the most popular types of PIC, for accessible and low-cost practical work

* Focuses on the 16F84 as the starting point for introducing the basic architecture of the PIC, but also covers newer chips in the 16F8X range, and 8-pin mini-PICs

Click here to download PIC Microcontrollers, Second Edition: An Introduction to Microelectronics

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Practical Aspects of Embedded System Design using Microcontrollers

2009-05-24T13:01:00.002+07:00

Second in the series, Practical Aspects of Embedded System Design using Microcontrollers emphasizes the same philosophy of "Learning by Doing" and "Hands on Approach" with the application oriented case studies developed around the PIC16F877 and AT 89S52, today's most popular microcontrollers. Readers with an academic and theoretical understanding of embedded microcontroller systems are introduced to the practical and industry oriented Embedded System design. When kick starting a project in the laboratory a reader will be able to benefit experimenting with the ready made designs and 'C' programs. One can also go about carving a big dream project by treating the designs and programs presented in this book as building blocks. Practical Aspects of Embedded System Design using Microcontrollers is yet another valuable addition and guides the developers to achieve shorter product development times with the use of microcontrollers in the days of increased software complexity.

Going through the text and experimenting with the programs in a laboratory will definitely empower the potential reader, having more or less programming or electronics experience, to build embedded systems using microcontrollers around the home, office, store, etc. Practical Aspects of Embedded System Design using Microcontrollers will serve as a good reference for the academic community as well as industry professionals and overcome the fear of the newbies in this field of immense global importance.

About the Author

The proposed book will complement Springer's rich collection of books on embedded systems and especially the book "Exploring C for Microcontrollers - A Hands on Approach" authored by the same group in 2007

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Autorange Capacitance Meter with PIC16F873A

2009-05-23T12:10:00.005+07:00

Finally, I managed to persuade myself to make a really powerful capacitance meter. This is an autoranged version, which means one does not need to adjust the range settings. Furthermore, the measuring range is quite large, from 5pF all the way to 2600uF. It is all taken care of by the PIC16F873A inside the circuit.

It is based on a very simple circuit analysis principle of charging and discharging of capacitors in an RC circuit.

Tau = RC, where Tau is the Time constant of any given RC circuit. The voltage at any time t across the capacitor is given as,

Vcap = E[1 - e^ (t/RC)]

Substituting t with Tau = RC,
Vcap = 0.632E or 63.2 % of the charging voltage, for 5V it will be about 3.16V. This will be the reference voltage for the comparator module on board the PIC16F873A.

The other input to the comparator is the actual capacitor's voltage itself.

The capacitance meter begins by discharging the capacitor fully. Then it charges it and waits until the voltage across the capacitor reaches 0.632Vcc. The time is then captured and the capacitance is computed using Tau = RC. A 16 bit division routine written by Andy Warren is used for this project. The result is then displayed on the LCD. The process will then repeat itself every subsequent 0.255s.

The initial tests on the breadboard indicated some small problems. It appears that even the breadboard itself contains stray capacitance which may greatly affect readings, especially the readings on less then 100pF ranges.

To correct for this problem, I implemented 2 push buttons that can help calibrate the capacitance meter. Calibration is a simple task of just pushing the buttons until the capacitance reading reads 00000.00pF when there is not capacitors connected. Also, to prevent calibration at every time the meter is used, I also implemented a button to save the calibration settings on the EEPROM of the PIC16F873A. The PIC loads the setting everytime the device gets powered on.

Download File Project

Basic Electricity and Electronics for Control: Fundamentals and Applications, 3rd Edition

2009-05-23T12:04:00.001+07:00

This class-tested book gives you a familiarity with electricity and electronics as used in the modern world of measurement and control. Integral to the text are procedures performed to make safe and successful measurements of electrical quantities. It will give you a measurement vocabulary along with an understanding of digital and analog meters, bridges, power supplies, solid state circuitry, oscilloscopes, and analog to digital conversions. This book is about behavior, not design, and thus lends itself to an easy-to-understand format over absolute technical perfection. And where possible, applications are used to illustrate the topics being explained.

The text uses a minimum of mathematics and where algebraic concepts are utilized there is sufficient explanation of the operation, so you may see the solution without actually performing the mathematical operations.

This book is student centered. It has been developed from course materials successfully used by the author in both a college setting and when presented as short course study classes by ISA. These materials have been successful because of the insistence on practicality and solicitation of student suggestions for improvements. Basic Electricity and Electronics for Control will enhance student success in any industrial or technical school setting where basic technician training is to take place.

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Op Amps for Everyone

2009-05-23T11:58:00.002+07:00

The op amp IC has become the universal analog IC because it can perform all analog tasks. OP AMPS FOR EVERYONE provides the theoretical tools and practical know-how to get the most from these versatile devices. This new edition substantially updates coverage for low-speed and high-speed applications, and provides step by step walkthroughs for design and selection of op amps and circuits.

* Modular organization allows readers, based on their own background and level of experience, to start at any chapter

* written by experts at Texas Instruments and based on real op amps and circuit designs from TI

* NEW: large number of new cases for single supply op amp design techniques, including use of web-based design tool

* NEW: complete design walk-through for low-speed precision op amp selection and circuit design

* NEW: updates, including new techniques, for design for high-speed, low distortion applications.

* NEW: extensive new material on filters and filter design, including high-speed filtering for video and data

Click here to download Op Amps for Everyone

Super Converter

2009-05-21T22:41:00.003+07:00

Super Converter is an application for measurement units conversion. This software easily converts various measurement values into any other possible ones. Inches to centimetres, pounds to kilograms, Fahrenheit to Celsius... and more than 30 other conversions, grouped according to categories. Super Converter also calculates the values of many mathematical functions, as well as makes it possible to conduct geometric constructions and calculations for some figures.

This software tool is suitable fo any engineer. The list of the measurement unit conversion are covered Density, Distance/Length, Drill/Tap, Electrical, Exponents, Flow, Formulas, Force, Force per unit length, Fractions, Geometry, Heat, Light, Mass Per Unit Area, Mass Per Unit Length, Numbers, Power, Pressure, Resistors, Radiation, Temperature, Time, Torque, Velocity, Viscosity, Volume, Weight/Mass, Windchill, Wire Gage, Work, Acceleration, Angular Distance, Angular Velocity, Area, Concentration, Data Storage, Data Transfer.

Click Here to Download Super Converter

CodeVisionAVR

2009-05-21T22:18:00.002+07:00

CodeVisionAVR is a C cross-compiler, Integrated Development Environment and Automatic Program Generator designed for the Atmel AVR family of microcontrollers. The program is a native 32bit application that runs under the Windows 95, 98, NT 4.0, 2000 and XP operating systems. The C cross-compiler implements nearly all the elements of the ANSI C language, as allowed by the AVR architecture, with some features added to take advantage of specificity of the AVR architecture and the embedded system needs. The compiled COFF object files can be C source level debugged, with variable watching, using the Atmel AVR Studio debugger version 3.50 or later.

The Integrated Development Environment (IDE) has built-in AVR Chip In-System Programmer software that enables the automatical transfer of the program to the microcontroller chip after successful compilation/assembly.The In-System Programmer software is designed to work in conjunction with the Atmel STK500, Kanda Systems STK200+/300, Dontronics DT006, Vogel Elektronik VTEC-ISP and MicroTronics ATCPU, Mega2000 development boards.

Click here to download CodeVisionAVR

LabVIEW - Getting Started

2009-05-18T08:54:00.047+07:00

1. Launch LabVIEW (if it's been open, you can quit it first).

2. At the LabVIEW Getting Started dialog, click Blank VI to create a new blank VI (the Blank VI option is found under the New heading, and you have to click on the "Blank VI" text, not the icon). An "Untitled 1" VI front panel will appear on your screen.

Go to the floating Controls palette and navigate (by clicking) to the Modern Graph, subpalette, shown in Figure 17. If the Controls palette isn't visible, select View Controls Palette from the menu to make it visible. Also, make sure the front panel window is active, or you will see the Functions palette instead of the Controls palette.

Figure 17. Modern Graph palette showing the Waveform

Chart and various other charts and graphs

On the Graph subpalette, select Waveform Chart by clicking it with the mouse button.

You will notice that, as you run the cursor over the icons in the Controls palette and subpalettes, the selected button or icon's name appears in a tip strip, as shown in Figure 17.

Positioning Tool

You will see the outline of a chart with the cursor "holding" it, as shown in Figure 18. Position the cursor in a desirable spot on your front panel and click. The chart magically appears exactly where you placed it, as shown in Figure 3.19. If you want to move it, select the Positioning tool from the Tools palette, and then drag the chart to its new home. If the Tools palette isn't visible, select View , Tools Palette from the menu.

Figure 18. Waveform Chart after it has been

dragged onto the front panel (and before it has been dropped)

Figure 19. Waveform Chart after it has been dropped onto the front panel

3. Go back to the Modern subpalette; then navigate into Boolean subpalette, and choose Stop Button (see Figure 20).

Figure 20. Modern , Boolean palette showing the

Stop Button and other Boolean controls and indicators

Place it next to the chart, as shown in Figure 21.

Figure 21. Your VI front panel, after

adding a Waveform Chart and Stop Button

4. Now change the chart's Y-axis scale range from -10 thru +10 to 0 thru 1. Highlight the number "10" (Y-axis range max) by click-dragging or by double-clicking on it with the Text Edit tool. Now type in 1.0 and click on the enter button that appears in the Toolbar at the top of the window. Change -10 (Y-axis range min) to 0 in a similar manner.

Enter Button

5. Switch to the block diagram by selecting Show Block Diagram from the Window menu. You should see two terminals already there, as shown in Figure 22.

Figure 22. Your VI block diagram, showing the

Stop Button and Waveform Chart terminal

6. Now you will put the terminals inside a While Loop to repeat execution of a segment of your program. Go to the Programming , Structures subpalette of the floating Functions palette and select the While Loop (see Figure 23). Make sure the block diagram window is active, or you will see the Controls palette instead of the Functions palette.

Figure 23. Programming , Structures palette showing

a While Loop and other LabVIEW structure

Your cursor will change to a little loop icon. Now enclose the DBL and TF terminals: Click and hold down the mouse button while you drag the cursor from the upper-left to the lower-right corners of the objects you wish to enclose (see Figure 24).

Figure 24. Dragging the mouse cursor around a region of code

When you release the mouse button, the dashed line that is drawn as you drag will change into the While Loop border (see Figure 25). Make sure to leave some extra room inside the loop.

Figure 25. A While Loop containing the code

that was enclosed by the dragged region

7. Go to the Functions palette and select Random Number (0-1) from the Programming , Numeric subpalette. Place it inside the While Loop.

8. With the Positioning tool active, arrange your diagram objects so that they look like the block diagram in Figure 26.

Positioning Tool

Figure 26. Your block diagram after

placing the Random Number (0-1) function

9. With the Wiring tool active, click once on the Random Number (0-1) icon, drag the mouse over to the Waveform Chart's terminal, and click again (see Figure 27).

Figure 27. Your block diagram, as you

drag a wire from the Random Number (0-1)

function to the Waveform Chart terminal.

You should now have a solid orange wire connecting the two icons, as shown in Figure 28. If you mess up, you can select the wire or wire fragment with the Positioning tool and then hit the key to get rid of it. Now wire the Boolean TF terminal to the conditional terminal of the While Loop. The loop will execute while the switch on the front panel is FALSE (not pressed down) and stop when the switch becomes TRUE (pressed down).

Figure 28. Your block diagram after

completing the wiring task

10. You should be about ready to run your VI. First, switch back to the front panel by selecting Show Front Panel from the Window menu. Now click on the run button to run your VI. You will see a series of random numbers plotted continuously across the chart. When you want to stop, click on the stop Boolean button using the Operating tool (see Figure 29).

Figure 29. Your VI front panel

after pressing the Run button

11. Create a directory or folder called MYWORK in a convenient location (such as your home or documents directory). Save your VI in your MYWORK directory or folder by selecting Save from the File menu and pointing out the proper location to save to. Name it Random Number.vi.

AVR / 89S Microcontrollers programmer compatible with AVR910

2009-05-17T10:38:00.001+07:00

Programmer it is executed on the basis of the driver from Objective Development and it is completely compatible on commands with original programmer AVR910 from ATMEL. The description of the original circuit programmer can be taken in Application Note AVR910: In-System Programming , and the list of supported commands can be seen in Application Note AVR109: Self Programming

the Design:

The circuit programmer is resulted in figure below. Safety fuse F1 serves for protection of lines of port USB against casual short circuit on circuits of programmer. Diodes VD1, VD2 - with a direct power failure ~0,6 … 0,7В, are intended for downturn of a power of microcontroller DD1 up to 3,6 V. Light-emitting diodes VL1, VL2 signal about the current actions programmer, and, accordingly, designate modes of reading and recording. Light-emitting diode VL3 serves for the signal system of submission of a power on programmer.

The jumper J1-J2 serves as for initial programming the microcontroller (close J1 - MODify), and for use as a socket programmer (close J2 - NORMal). Resistors R10 - R14 are intended for the coordination of levels of signals of the controller programmer and the programmed controller.

Speed for port SPI it is equal 187,5 kHz. It allows to program controllers with clock frequency approximately from 570 kHz for tiny/mega, 750 kHz for 90S and 7,5 MHz for 89S. Controllers are programmed from 10 till 30 seconds together with verification depending on volume FLASH of memory and clock frequency. On conclusion LED of socket ISP the meander with frequency of 1 MHz for "revival" uCU at which have been wrongly programmed fuse bits, responsible for clocking is removed. The signal is generated constantly and does not depend on an operating mode of programmer

Programmer it was tested with programs AVRProg v.1.4 (enters into a package AVRStudio ), ChipBlasterAVR v.1.07 Evaluation , AVROSP (ATMEL AVR Open Source Programmer) , CodeVisionAVR . Besides programmer it was tested with the program AVRDUDE , however, the program with given programmer is not compatible, as not all commands of the report AVR910 fulfils correctly. Programmer allows to program all controllers AVR supporting ISP (In System Programming - Programming In System), and as uCU series 89S - 89S53 and 89S8252. At present with the set forth above programs programming controllers 89S53, 89S8252, 90S2313, 90S8515, ATtiny26, ATtiny45, ATtiny2313, ATmega48, ATmega8, ATmega8515, ATmega8535, ATmega16, ATmega32, ATmega64 ATmega128, AT90CAN128 is tested

I strongly recommend to repeat the circuit one-in-one, to throw out "superfluous" details from the circuit can result or in wrong functioning programmer, or to possible failure USB of port on РС, for what, naturally, I do not carry what responsibility.

Insertion FUSE BITS:

For normal functioning the controller in the circuit it is necessary, that were programmed (bats SPIEN, CKOPT and SUT0 are established in "0"). Usually uCU, going from a factory, i.e. new, have already programmed bats SPIEN. As it is desirable (but it is not necessary) to program (to establish in "0") bats BODEN that will resolve job built - in uCU broun-out the detector. At not programmed to bat BODLEVEL level operations broun-out the detector there will be at a level of 2,4...2,9 Volt... Other bats should be not programmed (are established in "1")

Installation:

Windows XP

To stitch the controller. To connect newly-baked programmer to РС through free socket USB. OS will find the new device - AVR910 USB Programmer , at the offer automatically to find the driver, to refuse, and to specify a way to a file prottoss.avr910.usb.inf . At the prevention{warning}, that the driver has no digital signature, to send OS in erotic travel. Small problems at me have arisen, when, after installation, program AVRProg v. 1.4 could not find programmer as OS has appropriated to him number COM9. After monitoring ports appeared, that AVRProg searches for the device only on ports COM1 - COM4. To change number of port it is possible if to go in the manager of devices in: AVR910 USB Programmer-> Properties> Parameters of port-> In addition-> Number of COM-port

Windows 2000

Basically, installation does not differ from described above for Windows XP, but there is one BUT - delays in the driver usbser.sys spoil a chain of commands from on PC up to Soft programmer and, circuit of answers back from programmer up Soft to on PC... I yet have not established the Problem, but there is a decision... Certainly not the most beautiful, but works reliably:-) It is necessary to replace a file usbser.sys in system folders Windows 2000 on similar from Windows XP. These are folders ...\winnt\system32\drivers \ and ...\winnt\system32\dllcashe \ . The file usbser.sys from Windows XP SP1 can be taken here . It is natural, that the driver should be substituted having loaded under other OS (for example from a loading disk). As nucleus of these two OS are very similar, the driver from XP fine feels itself under 2000:--) At least, I have tested some more devices, pretending to be USB CDC Class, and all of them worked as usually... Attempts install the driver from XP through an adjusting file, unfortunately, in anything have not resulted. If who that knows, how it can be made, I shall be grateful.

Files:

All archives contain a file of an insertion, an adjusting inf-file and the circuit in format Adobe pdf. Except for it old versions contain the description as old html pages.

avr910_usb_programmer.files.ver.1.01.rar the Version from 25.08.2006. Frequency trim SPI, that adds speed of programming a little, however, it, there are problems with job on some computers because of timeout expectations ON programmer

avr910_usb_programmer.files.ver.1.02.rar the Version from 21.09.2006. No frequency trim, but for that generation of a meander on conclusion LED of a ISP-socket has appeared. There is a mistake in an insertion, connected with an establishment on conclusion RESET of a ISP-socket a broad gully. "0" at the first inclusion programmer. The conclusion remains in such status before the first programming or an input in the menu of installation fuse bits...

avr910_usb_programmer.files.ver.1.03.rar the Version from 31.10.2006. Is corrected a mistake of version 1.02.

avr910_usb_programmer.files.ver.1.04.rar the Version from 16.12.2006. internal pull-up the resistor connection Is added to an input MISO uCU programmers during programming target uCU. Probably, it will be useful at reading payments with the lowered voltage power, and in general, I think, will positively have an effect on reliability of reading programmed uCU.

Basic USB Communication (RS-232 Emulation Method) With PIC18F4550

2009-05-17T10:00:00.000+07:00

With the continuous decrease in the use of COM Port devices and COM Ports itselt, the need to migrate to the USB has become increasingly important. = ( . Just take a look at the laptop PCs nowadays, it is a miracle if you can even find just 1 COM Port on it. But the good news is... we have got a simple (very simple in fact) way of migrating from the old RS232 to USB, that is via RS232 Emulation method. This method alone has got quite a number of ways to implement, e.g. using USB Convertor ICs, like the FTDI232BM (this is UART-USB conversion), the Philips PDIUSBD11 (this is I2C conversion to USB) and many more. Sometime last year, Microchip released the USB 2.0 compatible microcontrollers, i.e. PIC18F4550, 18F2550 and etc. Presented here, is the example of using the CDC firmware provided by Microchip to emulate a COM Port when the device is connected to the USB Port.

When the device is connected to the computer, a Virtual COM Port (VCP) will be created. This is shown at the Device Manager Window under Ports(COM & LPT). In this case, COM5 was created when the PIC18F4550 was attached to the USB Port. It may be interesting to note that if you plug in your PIC in different USB ports, the
VCP created will be different.

Here, I modified the CDC firmware provided by Microchip and wrote a Visual Basic programme to communicate with the device. An important thing to note when using the firmware and this schematics is that... to PLACE REMARKS ON THE FOLLOWING 2 LINES AT USBCFG.H like this...

//#define USE_SELF_POWER_SENSE_IO
//#define USE_USB_BUS_SENSE_IO

if not the when you attach the PIC to the USB Port, it will disconnect itself immediately soon after!

The concept of baud rates, parity bits and flow control is not important in this method of RS232 emulation as most of these matters are taken care of by Windows XP's internal drivers. Therefore, the settings for MSComm for these properties can be omitted altogether. It will still work.The VB software controls the 2 LEDs connected at RD2 and RD3 besides reading the analog voltage of the potentiometer connected at RA0. The correct VCP has to selected before the software can communicate with the PIC18F4550.

One last thing is that, when you want to switch back to the bootloader mode, just hold on to S2 (Enter Boot) while tapping S1 (Reset). When the bootloader firmware in the PIC detects a HIGH on S2, it will enter Bootloader mode where you can use the PDFSUSB.EXE to programme, erase or to read the PIC via the USB Port. When I do this project, I first went thru the quick USB tutorial at the website above before writing the firmware to communicate with the VB software. I would advice you to do the same too. The next time, I will present the HID version of USB Communication. =)

Schematics: USB_USARTSchem.jpg
Microchip C18 modified CDC firmware : cdc.zip
Visual Basic 6 programme : usbusart.zip

PIC Simulator

2009-05-17T09:53:00.000+07:00

PIC SIMULATOR IDE PIC Simulator IDE is powerful application that supplies PIC developers with user-friendly graphical development environment for Windows

AVR MONITORS / DEBUGGERS

2009-05-17T09:43:00.000+07:00

AVR Studio version 1.42, a C and Assembler source level debugger for the AT90S

AVR Assembler/Disassembler

2009-05-17T06:42:00.000+07:00

PIC Disassembler

2009-05-17T06:33:00.000+07:00

PIC Microcontroller Assembler

2009-05-16T22:46:00.000+07:00

C Compiler for MCS-51 compatible

2009-05-16T22:38:00.000+07:00

MCS-51 simulator/emulator

2009-05-16T22:34:00.000+07:00

MONITORS/DEBUGGERS for MCS-51,8051 compatible

2009-05-16T22:31:00.000+07:00

BASIC for 8051 compatible

2009-05-16T22:18:00.000+07:00

Disassembler for MCS-51 Compatible Microcontroller

2009-05-16T21:59:00.000+07:00

Assembler for MCS-51 compatible Microcontroller

2009-05-16T21:34:00.000+07:00

RS232 to RS485 Converter

2009-05-16T21:19:00.001+07:00

This is a small RS232 to RS485 converter project it use for convert RS232 signal level to RS485 level multidrop.It can use with 32 slave to comunicate with PC and embedded systems board for long distance less than 1.2Km( 4000 feet).

Specification

- 9-12Vdc power supply
- small size only 2.8" X 1.45 "
- use for RS485 multidrop 2 wire connection.
- Direct connect with PC on DB9 connecter.
- Use RTS signal to control direction .
- 32 Slaves (up to 256 slaves with some transceiver i.e. MAX3088)

In the Figure 1 J1 and J2 use for jump R terminate(120) at the
end of communication line or last slave.The 75176 use for
transceiver.
RTS active (logic 0 or -3 to -15V) when we need to send data .

Zipped file consist of :
- Schematic
- PCB

Minimum System Board For AT89SXXXX

2009-05-16T20:50:00.000+07:00

Features

Support ATMEL AT89S series such as AT89S51, AT89S52, AT89S53, AT89S8252.(DIP 40 pin devices)
Use In-System Programming(ISP).Low voltage programming
RS232 X 1 .
5V regulate on-board.
No need any tools or programmer devices .
connector for all I/O.
Requite one PC parallel port for ISP.
Software supports for All Windows.
easy to build your own single side PCB.
Require power supply from DC adpaptor 9-12VDC or AC

How to use ATMEL ISP.

To use this ATMEL ISP board you need to download software ISP-3v0 developed by Muhammad Asim Khan and distributed by Prof. Wichit 's website or download at the buttom on this page.

Software ATMEL ISP V3.0

After download software.

1. Connect ATMEL ISP cable to PC parallel port and power supply. (see Fig.5)
2. Run software ISP3.0 for Windows95/98/ME use ISP-3v0.exe and WindowsXP/2000/NT use ISP-XP.bat .
3. Select your devices from drop down list menu.
4. Click "Open file" to open hex file.
5. Click "Write" to program device.

How to use RS232 port.

To use RS232 port ,first build a simple RS232 cable.

Download Schematic and PCB

SubVIs, the Icon, and the Connector in LabVIEW

2009-05-16T15:02:00.000+07:00

A subVI simply refers to a VI that is going to be called by another VI. Any VI can be configured to function as a subVI. For example, let's say you create a VI called Mean.vi that calculates the mean value of an array. You can always run Mean.vi from its front panel (by pressing the run button on the toolbar), but you can also configure Mean.vi so that other VIs can call it as a function on their block diagram (they call Mean.vi as a subVI).

When your VI operates as a subVI, its controls and indicators receive data from and return data to the VI that calls it. A VI's icon represents it as a subVI in the block diagram of another VI. An icon can include a pictorial representation or a small textual description of the VI, or a combination of both.

The VI's connector functions much like the parameter list of a C or Pascal function call; the connector terminals act like little graphical parameters to pass data to and from the subVl. Each terminal corresponds to its very own control or indicator on the front panel. During the subVI call, the input parameter terminals are copied to the connected controls, and the subVI executes. At completion, the indicator values are copied to the output parameter terminals.

Figure 14. An icon and its underlying connector

Every VI has a default icon, which is displayed in the icon pane in the upper-right corner of the panel and diagram windows. The default icon is depicted in Figure 15.

Figure 15. The VI icon pane in the

upper-right corner of a VI front panel

A VI's connector is hidden under the icon; access it by choosing Show Connector from the front panel icon pane pop-up menu (we'll talk more about pop-up menus later). When you show the connector for the first time, LabVIEW helpfully suggests a connector pattern that has twelve terminals (six on the left for inputs and six on the right for outputs). The default connector pane is depicted in Figure 16. You can select a different pattern if you desire, and you can assign up to 28 terminals before you run out of real estate on the connector.

Figure 16. The VI connector pane in

the upper-right corner of a VI front panel

Make a LabVIEW Project

2009-05-16T14:26:00.000+07:00

LabVIEW Projects

LabVIEW Projects allow you to organize your VI and other LabVIEW files as well as non-LabVIEW files, such as documentation and just about anything else you can think of. When you save your project, LabVIEW creates a project file (.lvproj). In addition to storing information about the files contained in your project, the project file stores your project's configuration, build, and deployment information.

You might be asking yourself: "Why do I need a project?" There are a lot of reasons, but a better question might be to ask: "When don't I need a project?" The answer to this is very simple. You don't need a project if you are only going to create one or two VIs and you are more interested in collecting and analyzing data, than you are in the VIs that you use to collect and analyze data. However, if you are interested in managing your VIs as software, you should organize your VIs in a LabVIEW Project.

Project Explorer Window

The Project Explorer window is where you will create and edit your LabVIEW Projects. Figure 7 shows an empty project. You can create an empty project by selecting File>>New . . . from the menu and then selecting Empty Project from the dialog box.

Figure 7. Project Explorer window showing

a new, empty LabVIEW project

The project appears as a tree with several items. The root item is the Project root, which shows the name of the project file and contains all of the project items. The next item is My Computer, which represents the local computer as a target in the project.

A target is a location where your VIs will be deployed. A target can be your local computer, a LabVIEW RT controller, a Personal Digital Assistant (PDA), a LabVIEW FPGA device, or anywhere you can run LabVIEW VIs. You can add targets to your project by right-clicking on the project root and selecting New>>Targets and Devices from the shortcut menu. In order to be able to add additional targets to your project, you will need to install the appropriate LabVIEW add-on module. For example, the LabVIEW Real-Time, FGPA, and PDA modules allow you to add those targets to your project.

Beneath the My Computer target are Dependencies and Build Specifications. Dependencies are items that VIs in the project require. Build specifications are the rules that define how your application will be deployed.

Project Explorer Toolbars

The Project Explorer has several toolbars that allow you to easily perform common operations. These are the Standard, Project, Build, and Source Control toolbars, shown in Figure 8 (respectively, from left to right).

Figure 8. Project Explorer toolbars

You can choose which of these toolbars are visible from the View>>Toolbars menu, or by right-clicking on the toolbar and selecting the desired toolbar from the pop-up menu that appears (see Figure 9).

Figure 9. Toolbar pop-up menu showing

which toolbars are visible (checked)

Adding Items to Your Project

You can add items to your project, beneath the My Computer target. You can also create folders, to better organize the items in a project. There are a variety of ways to add items to your project. The pop-up shortcut menu is probably the easiest way to add new VIs and create new folders, as shown in Figure 10.

Figure 10. Adding a new VI to a LabVIEW

project from the pop-up menu of

My Computer in the Project Explorer

You can also add items from the pop-up menu, but the easiest way (in Windows and Mac OS) is to drag the item or directory from disk into the Project Explorer, as shown in Figure 11. You can also drag a VI's icon (in the upper-right corner of a front panel or block diagram window) to the target.

Figure 11. Drag and drop to

add a VI into project

Project Folders

Project folders are used to organize your project files. For example, you could create a folder for your subVIs and another folder for your project documentation, as shown in Figure 12.

Figure 3.12. The Project Explorer

showing project folders used to

organize project files

Project folders are virtual, which means that they do not necessarily represent folders on disk (although you might choose to create project folders that reflect the organization of your folders on disk). One side effect of this is that after you add a directory on disk to a project, LabVIEW will not automatically update the project folder contents to reflect changes made to the directory on disk. You will have to synchronize these manually, if you wish to do so.

Removing Items from a Project

Items can be removed from the project by right-clicking the item in the Project Explorer and selecting Remove from the pop-up shortcut menu, as shown in Figure 13.

Figure 3.13. Removing items from a

project using the pop-up menu

Alternatively you can delete an item by selecting the item in the Project Explorer and then pressing the key or pressing the Delete button on the Standard toolbar. Removing an item from a project does not delete the corresponding item on disk.

Building Applications, Installers, DLLs, Source Distributions, and Zip Files

The project environment provides you with the ability to create built software products from your VIs. To do this, pop up on the Build Specifications node in the Project Explorer window and select a build output type from the New>> submenu. You can choose from the following options:

Application Use stand-alone applications to provide other users with executable versions of VIs. Applications are useful when you want users to run VIs without installing the LabVIEW development system. Windows applications have an .exe extension, Mac OS X applications have an .app extension, and Linux applications have no file extension.
Installer (Windows only) Use installers to distribute stand-alone applications, shared libraries, and source distributions that you create with the Application Builder. Installers that include the LabVIEW Run-Time Engine are useful if you want users to be able to run applications or use shared libraries without installing LabVIEW.
Shared Library Use shared libraries if you want to call VIs using text-based programming languages, such as NI LabWindows/CVI, Microsoft Visual C++, and Microsoft Visual Basic. Using shared libraries provides a way for programming languages other than LabVIEW to access code developed with LabVIEW. Shared libraries are useful when you want to share the functionality of the VIs you build with other developers. Other developers can use the shared libraries but cannot edit or view the block diagrams unless you enable debugging. Windows shared libraries have a .dll extension. Mac OS X shared libraries have a .framework extension. Linux shared libraries have an .so extension.
Source Distribution Use source distributions to package a collection of source files. Source distributions are useful if you want to send code to other developers to use in LabVIEW. You can configure settings for specified VIs to add passwords, remove block diagrams, or apply other settings. You also can select different destination directories for VIs in a source distribution without breaking the links between VIs and subVIs.
Zip File Use zip files when you want to distribute files or an entire LabVIEW project as a single, portable file. A zip file contains compressed files, which you can send to users. Zip files are useful if you want to distribute instrument driver files or selected source files to other LabVIEW users. You also can use the Zip VIs (found on the Programming>>File I/O>>Zip palette) to create zip files programmatically.

Each of these build output types has its own set of build specifications. A build specification contains all the settings for the build, such as files to include, directories to create, and settings for directories of VIs.

Front Panels and Block Diagram in LabVIEW

2009-05-16T13:33:00.000+07:00

Front Panels

Simply put, the front panel is the window through which the user interacts with the program. When you run a VI, you must have the front panel open so that you can input data to the executing program. You will also find the front panel indispensable because that's where you see your program's output. Figure 3.1 shows an example of a LabVIEW front panel.
Front Panels

Figure 1. LabVIEW front panel

Controls and Indicators

The front panel is primarily a combination of controls and indicators. Controls simulate typical input objects you might find on a conventional instrument, such as knobs and switches. Controls allow the user to input values; they supply data to the block diagram of the VI. Indicators show output values produced by the program. Consider this simple way to think about controls and indicators:

Controls = Inputs from the User = Source of Data
Indicators = Outputs to the User = Destinations or "Sinks" for Data

They are generally not interchangeable, so make sure you understand the difference.

You "drop" controls and indicators onto the front panel by selecting them from a subpalette of the floating Controls palette window and placing them in a desired spot. Once an object is on the front panel, you can easily adjust its size, shape, position, color, and other properties.

Block Diagrams

The block diagram window holds the graphical source code of LabVIEW VIs. LabVIEW's block diagram corresponds to the lines of text found in a more conventional language like C or BASICit is the actual executable code. You construct the block diagram by wiring together objects that perform specific functions. In this section, we will discuss the various components of a block diagram: terminals, nodes, and wires.

The simple VI shown in Figure 2 computes the sum of two numbers. Its diagram in Figure 3 shows examples of terminals, nodes, and wires.

Figure 2. The front panel of Add.vi

contains controls for data input and

indicators for data display

Figure 3. The block diagram of Add.vi

contains terminals, nodes, and

wires (the functional source code)

When you place a control or indicator on the front panel, LabVIEW automatically creates a corresponding terminal on the block diagram. By default, you cannot delete a block diagram terminal that belongs to a control or indicator, although you may try to your heart's content. The terminal disappears only when you delete its corresponding control or indicator on the front panel.

You can allow the deletion of panel terminals on the block diagram by enabling the Delete/copy panel terminals from diagram option in the Block Diagram category of the Tools>>Options dialog (we will learn more about the LabVIEW Options dialog in Chapter 15). However, this is only recommended if you are very comfortable and experienced with editing LabVIEW VIs. It is very easy to mistakenly delete front panel controls and indicators without realizing it, because you may not be paying much attention to the front panel while editing the block diagram.

Control terminals have thick borders along with an arrow pointing out from the right, while indicator borders are thin and have an arrow pointing in from the left. It is very important to distinguish between the two because they are not functionally equivalent (Control=Input=data source and Indicator = Output = data sink, so they are not interchangeable).

You can think of terminals as entry and exit ports in the block diagram, or as sources and destinations. Data that you enter into Numeric Control 1 (shown in Figure 4) exits the front panel and enters the block diagram through the Numeric Control 1 terminal on the diagram. The data from Numeric Control 1 follows the wire and enters the Add function input terminal. Similarly, data from Numeric Control 2 flows into the other input terminal of the Add function. Once data is available on both input terminals of the Add function, it performs its internal calculations, producing a new data value at its output terminal. The output data flows to the Numeric Indicator terminal and reenters the front panel, where it is displayed for the user.

Figure 3.4. Block diagram with a control

(input/source) terminal, an indicator

(output/sink) terminal, and a wire through

which data will flow

View Terminals as Icons

Block diagram terminals have a View As Icon option (available from their pop-up menus), which causes them to be viewed as Icons. A terminal viewed as an icon is larger (than with the setting turned off) and contains an icon that reflects the terminal's front panel control type. With the View As Icon option turned off, a terminal will be more compact and display the data type more predominantly. The functionality is exactly the same for either setting; it's just a matter of preference.

Figure 5 shows the terminals of several different front panel controls with the View As Icon option selected (top row) and with the option not selected (bottom row).

Figure 3.5. Terminals with View As

Icon setting enabled (top row) and

disabled (bottom row)

This setting is configurable for each terminal on the block diagram. You can choose whether terminals will be placed onto the block diagram as icons, by checking the Place front panel terminals as icons setting in the Block Diagram category of the Tools>>Options dialog. This LabVIEW option is turned on, by default.

Nodes

A node is just a fancy word for a program execution element. Nodes are analogous to statements, operators, functions, and subroutines in standard programming languages. The Add and Subtract functions represent one type of node. A structure is another type of node. Structures can execute code repeatedly or conditionally, similar to loops and case statements in traditional programming languages. LabVIEW also has special nodes, called Formula Nodes, which are useful for evaluating mathematical formulas or expressions. In addition, LabVIEW has very special nodes called Event Structures that can capture front panel and user-defined events.

Wires

A LabVIEW VI is held together by wires connecting nodes and terminals. Wires are the data paths between source and destination terminals; they deliver data from one source terminal to one or more destination terminals.

If you connect more than one source or no source at all to a wire, LabVIEW disagrees with what you're doing, and the wire will appear brokena wire can only have one data source, but it can have multiple data sinks.

Each wire has a different style or color, depending on the data type that flows through the wire. The block diagram shown in Figure 3 depicts the wire style for a numeric scalar valuea thin, solid line. The chart in Figure 6 shows a few wires and corresponding types.

Figure 6. Basic wire styles used in block diagrams

Dataflow ProgrammingGoing with the Flow

Because LabVIEW is not a text-based language, its code cannot execute "line by line." The principle that governs G program execution is called dataflow. Stated simply, a node executes only when data arrives at all its input terminals; the node supplies data to all of its output terminals when it finishes executing; and the data passes immediately from source to destination terminals. Dataflow contrasts strikingly with the control flow method of executing a text-based program, in which instructions are executed in the sequence in which they are written. This difference may take some getting used to. Although traditional execution flow is instruction driven, dataflow execution is data driven or data dependent.

Nuts and Volts - April 2009

2009-05-16T13:27:00.001+07:00

Click here to download Nuts and Volts - April 2009

Nuts and Volts - March 2009

2009-05-16T13:24:00.000+07:00

Click here to download Nuts and Volts - March 2009

Circuit Cellar April 2009

2009-05-15T15:43:00.000+07:00

Click here to download Circuit Cellar April 2009

Circuit Cellar March 2009

2009-05-15T15:41:00.001+07:00

Click here to download Circuit Cellar March 2009

Circuit Cellar February 2009

2009-05-15T15:37:00.000+07:00

Click here to download Circuit Cellar February 2009

Circuit Cellar January 2009

2009-05-15T15:31:00.000+07:00

Click here to download Circuit Cellar January 2009

50 MHz Frequency Counter

2009-05-15T15:07:00.000+07:00

This project is nice and small frequency counter that reads
frequency from 1 Hz to 50 MHz that I have modified from original designed by Weeder Technologies . I have designed new PCB to fit with 16X1 LCD and change source code for compatible with new small PCB

Specifications

- Auto-ranging with floating decimal point.
- Up to 7 digits displayed on 1X16 LCD.
- Auto-adjusting gate speed (0.1 sec to 1 sec).
- Microcontroller-based circuitry provides for simplicity, ease of assembly, and highly stable readout.
- Sensitivity approximately 100 mV RMS (100 Hz to 2 MHz), 800 mV RMS @ 50 MHz.
- Input overload protected.

Download Source Code Here

What Exactly Is LabVIEW, and What Can It Do for Me?

2009-05-15T09:43:00.000+07:00

LabVIEW, short for Laboratory Virtual Instrument Engineering Workbench, is a programming environment in which you create programs using a graphical notation (connecting functional nodes via wires through which data flows); in this regard, it differs from traditional programming languages like C, C++, or Java, in which you program with text. However, LabVIEW is much more than a programming language. It is an interactive program development and execution system designed for people, like scientists and engineers, who need to program as part of their jobs. The LabVIEW development environment works on computers running Windows, Mac OS X, or Linux. LabVIEW can create programs that run on those platforms, as well as Microsoft Pocket PC, Microsoft Windows CE, Palm OS, and a variety of embedded platforms, including Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), and microprocessors.

Using the very powerful graphical programming language that many LabVIEW users affectionately call "G" (for graphical), LabVIEW can increase your productivity by orders of magnitude. Programs that take weeks or months to write using conventional programming languages can be completed in hours using LabVIEW because it is specifically designed to take measurements, analyze data, and present results to the user. And because LabVIEW has such a versatile graphical user interface and is so easy to program with, it is also ideal for simulations, presentation of ideas, general programming, or even teaching basic programming concepts.

LabVIEW offers more flexibility than standard laboratory instruments because it is software-based. You, not the instrument manufacturer, define instrument functionality. Your computer, plug-in hardware, and LabVIEW comprise a completely configurable virtual instrument to accomplish your tasks. Using LabVIEW, you can create exactly the type of virtual instrument you need, when you need it, at a fraction of the cost of traditional instruments. When your needs change, you can modify your virtual instrument in moments.

LabVIEW tries to make your life as hassle-free as possible. It has extensive libraries of functions and subroutines to help you with most programming tasks, without the fuss of pointers, memory allocation, and other arcane programming problems found in conventional programming languages. LabVIEW also contains application-specific libraries of code for data acquisition (DAQ), General Purpose Interface Bus (GPIB), and serial instrument control, data analysis, data presentation, data storage, and communication over the Internet. The Analysis Library contains a multitude of useful functions, including signal generation, signal processing, filters, windows, statistics, regression, linear algebra, and array arithmetic.

Figure 1. The Space Industries Sheet Float Zone

Furnace is used for high-temperature superconductor

materials processing research in a microgravity

environment aboard the NASA KC-135 parabolic

aircraft. LabVIEW controls the industrialized

Mac OS-based system.

Because of LabVIEW's graphical nature, it is inherently a data presentation package. Output appears in any form you desire. Charts, graphs, and user-defined graphics comprise just a fraction of available output options. This book will show you how to present data in all of these forms.

LabVIEW's programs are portable across platforms, so you can write a program on a Macintosh and then load and run it on a Windows machine without changing a thing in most applications. You will find LabVIEW applications improving operations in any number of industries, from every kind of engineering and process control to biology, farming, psychology, chemistry, physics, teaching, and many others.

Dataflow and the Graphical Programming Language

The LabVIEW program development environment is different from standard C or Java development systems in one important respect: While other programming systems use text-based languages to create lines of code, LabVIEW uses a graphical programming language, often called "G," to create programs in a pictorial form called a block diagram.

Graphical programming eliminates a lot of the syntactical details associated with text-based languages, such as where to put your semicolons and curly braces. (If you don't know how text-based languages use these, don't worry. With LabVIEW, you don't need to know!)

Graphical programming allows you to concentrate on the flow of data within your application, because its simple syntax doesn't obscure what the program is doing. Figures 2 and 3 show a simple LabVIEW user interface and the code behind it.

Figure 2. User interface

Figure 3. Graphical code

LabVIEW uses terminology, icons, and ideas familiar to scientists and engineers. It relies on graphical symbols rather than textual language to define a program's actions. Its execution is based on the principle of dataflow, in which functions execute only after receiving the necessary data. Because of these features, you can learn LabVIEW even if you have little or no programming experience. However, you will find that a knowledge of programming fundamentals is very helpful.

How Does LabVIEW Work?

A LabVIEW program consists of one or more virtual instruments (VIs). Virtual instruments are called such because their appearance and operation often imitate actual physical instruments. However, behind the scenes, they are analogous to main programs, functions, and subroutines from popular programming languages like C or Basic. Hereafter, we will refer to a LabVIEW program as a "VI" (pronounced "vee eye," NOT the Roman numeral six, as we've heard some people say). Also, be aware that a LabVIEW program is always called a VI, whether its appearance or function relates to an actual instrument or not.

A VI has three main parts: a front panel, a block diagram, and an icon.

The front panel is the interactive user interface of a VI, so named because it simulates the front panel of a physical instrument (see Figure 4). The front panel can contain knobs, push buttons, graphs, and many other controls (which are user inputs) and indicators (which are program outputs). You can input data using a mouse and keyboard, and then view the results produced by your program on the screen.

Figure 4. A VI front panel

The block diagram is the VI's source code, constructed in LabVIEW's graphical programming language, G (see Figure 5). The block diagram is the actual executable program. The components of a block diagram are lower-level VIs, built-in functions, constants, and program execution control structures. You draw wires to connect the appropriate objects together to define the flow of data between them. Front panel objects have corresponding terminals on the block diagram so data can pass from the user to the program and back to the user.

Figure 5. A VI block diagram

In order to use a VI as a subroutine in the block diagram of another VI, it must have an icon with a connector (see Figure 6). A VI that is used within another VI is called a subVI and is analogous to a subroutine. The icon is a VI's pictorial representation and is used as an object in the block diagram of another VI. A VI's connector is the mechanism used to wire data into the VI from other block diagrams when the VI is used as a subVI. Much like parameters of a subroutine, the connector defines the inputs and outputs of the VI.

Virtual instruments are hierarchical and modular. You can use them as top-level programs or subprograms. With this architecture, LabVIEW promotes the concept of modular programming. First, you divide an application into a series of simple subtasks. Next, you build a VI to accomplish each subtask and then combine those VIs on a top-level block diagram to complete the larger task.

Modular programming is a plus because you can execute each subVI by itself, which facilitates debugging. Furthermore, many low-level subVIs often perform tasks common to several applications and can be used independently by each individual application.

Just so you can keep things straight, we've listed a few common LabVIEW terms with their conventional programming equivalents in Table 1.

Table 1. LabVIEW Terms and Their Conventional Equivalents

AVR ISP Programmer (In-Sytem programmer) for ATMEL

2009-05-15T05:05:00.000+07:00

Introduction:

This AVR ISP original by ATMEL you can found on "AVR software
and technical Library - April 2003" CD-rom.It small component count I design new PCB and change some component that easy to build small PCB.The new firmware was writen by John Samperi for AT90S2313 .This code can program more devices.

Specification

- Device support

Verified device

- Use power supply from target board
- RS-232 control at 19200 BPS
- Support AVR Studio 4

Schematic detail

The schematic for AVR ISP show in picture 1, IC1 DS275 use for RS-232 Driver becuase it small and no need external component IC2 AT90S2313 is the CPU to communication and receive command from PC that run AVR Prog to control target CPU. The wire from AVR ISP to target CPU not exceed 15 cm

This firmware compiled to run on crystal 4MHz ,so the target device must connect crystal 4MHz on XTAL1 and XTAL2 pin.But, if your target device use internal oscillator and enabled .its not need any external oscillator.

To use this AVR ISP with target device that run at 8MHz you can do this by recompile the firmware source code. Before recompile you need to change the line in source code as below

.equ xtal_8mhz=0 ; if 0 then 4MHz Xtal

Change to :

.equ xtal_8mhz=1 ; if 0 then 4MHz Xtal

After change firmware you can compiler it by Avrasm found from ATMEL web site

To use AVR ISP

Picture 3.Show how to use AVR ISP

Click here to Download
- Source code
- Object code(Hex)
- schematic
- AVRProg